Pd Ratio Research Articles

Association of Autoimmune Diseases with the Risk of Parkinson's Disease.

PD is a progressive neurodegeneration disease characterized by cardinal motor symptoms such as bradykinesia and tremor. The pathogenesis of PD remains unclear. It is hypothesized that immune system dysfunction may contribute to PD. Thus, autoimmune diseases may influence the risk of incident PD. We included 398,329 participants without PD at the baseline from UK Biobank. The association between 20 autoimmune diseases with PD was examined using cox hazards regression analyses, adjusting covariates like age, sex, and smoking status in the statistical models. Sensitivity analyses were conducted, adjusting for polygenic risk score and the reported source of PD, to check the robustness. After an average follow-up of 13.1 ± 0.816 years, 2,245 participants were diagnosed with incident PD. After multiple comparison correction, only multiple sclerosis (MS) reached statistical significance and showed an increased risk for incident PD. Compared with non-MS patients, the risk of incident PD in MS patients was 2.57-fold with age and sex being adjusted (95% CI, 1.59-4.14; adjust p value = 0.002). After adjusting lifestyle and other factors, the hazard ratio of incident PD in MS patients was 2.49 (95% CI, 1.55-4.02; adjust p value = 0.004). Excluding the self-reported PD cases in the sensitivity analysis, MS was a detrimental factor for incident PD (HR, 2.06; 95% CI, 1.56-4.05; adjust p value = 0.004). The link between MS and PD did not reach the statistical significance in the sensitivity analysis adjusting the PRS (adjust p value = 0.95). Our study provided evidence from observational analyses that MS was associated with an increased risk of PD. Further investigations should be performed to determine the causal association and potential pathophysiology between MS and PD.

Combined Efficacy of Nimotuzumab and Gemcitabine on the Treatment of Advanced Pancreatic cancer.

We sought to investigate whether the addition of nimotuzumab to gemcitabine would improve the treatment efficacy of advanced pancreatic cancer. This retrospective analysis involved a total of 98 hospitalized patients harboring advanced pancreatic cancer. Depending on the specific treatment, patients were divided into study groups and control groups. The clinical efficacy, adverse reactions, and follow-up results of the 2 groups were compared, and the physical status, CA724, CA19-9, and CEA levels before and after treatment were monitored and recorded. After treatment, PR ratio, SD ratio, ORR, and DCR in the study group were significantly higher than those in the control group, and PD ratio was significantly lower than that in the control group (P < 0.05) the KPS score after treatment in the study group was markedly higher than that of the control group (P < 0.05). After treatment, however, significantly lower levels of the 3 indicators were observed when compared with the control group (P < 0.05). Our study highlights a more superior combined efficacy of nimotuzumab and gemcitabine than the control regimen, exhibiting improved survival and reduced levels of CA724, CA19-9, and CEA in patients with advanced pancreatic cancer.

Preparation of palladium‐based catalysts and use for depolymerization of larch bark tannins

AbstractIn this study, we synthesized eight palladium‐based catalysts using two carriers, ZrO2 and MCM‐41. These catalysts were used for the degradation of condensed tannins extracted from larch bark. The average polymerization degree and degradation rate of the products were used as indicators to evaluate the efficiency of degradation. The effects of different Pd:Cu loading ratios under the same carrier conditions and the effects of different carriers under the same Pd:Cu loading ratio were investigated. The results revealed that when the carrier was kept constant, the Pd:Cu ratio of 1:1 exhibited the highest efficiency in degrading condensed tannins. Moreover, when the Pd:Cu loading ratio was the same, the degradation efficiency was higher when ZrO2 was used as the carrier. Based on these findings, the catalyst (Pd1‐Cu1)5/ZrO2 (where “1” are the molar ratios of Pd to Cu added during the preparation of the catalyst and where ‘5’ is the mass percentage of Pd/Cu metal to total catalyst, i.e., 5 wt%), with ZrO2 as the carrier and a Pd:Cu ratio of 1:1, demonstrated the highest degradation efficiency, with a degradation rate of 73.89%. This catalyst successfully reduced the average polymerization degree of condensed tannins from 9.5 to 2.48.

Ratio design of bimetallic Pd‐Rh nanoparticles on MoS2 nanosheets: Excellent electrocatalysts for hydrogen evolution reaction

The decrease in noble metal content presents an efficient approach to attain commercial, effective, and durable electrocatalysts for the hydrogen evolution reaction (HER) at a low fabrication cost. Nonetheless, achieving a proper balance between bimetallic loading ratios and HER performance remains challenging. In this study, a simple and environmentally friendly sonochemical method is employed to successfully synthesize bimetallic palladium–rhodium nanoparticles (Pd‐Rh) with varying ratios, confined within molybdenum disulfide (MoS2) nanosheets. Bimetallic Pd‐Rh/MoS2 composite with different ratios of Pd:Rh is synthesized by adjusting the feed ratio of Pd and Rh precursors (1:4, 1:1, and 4:1). The HER electrocatalytic activity of the bimetallic Pd1‐Rh1/MoS2 composite exhibits the lowest overpotential and a superior Tafel slope, closely rivaling the electrocatalytic activity of the commercial 20 wt% Pt/C. Furthermore, the bimetallic Pd1‐Rh1/MoS2 composite exhibits remarkable stability and durability, with almost negligible performance decay after 2000 cycles. These outstanding HER electrocatalytic properties of the bimetallic composite result from a higher number of active sites, a significantly larger electrochemically active surface area, reduced charge‐transfer resistance, and a larger double‐layer capacitance. These factors collectively facilitate faster adsorption and desorption of hydron on the surface of electrocatalyst.

The Oxidation Performance of a Carbon Soot Catalyst Based on the Pt-Pd Synergy Effect

Pt-Pd-based noble metal catalysts are widely used in engine exhaust aftertreatment because of their better carbon soot oxidation performance. At present, the synergistic effect of Pt and Pd in CDPFs, which is the most widely used and common doping method, in catalyzing the combustion of carbon smoke has not been reported, and it is not possible to give an optimal doping ratio of Pt and Pd. This paper investigates the carbon soot oxidation performance of different Pt/Pd ratios (Pt/Pd = 1:0, 10:1, 5:1, 1:1) based on physicochemical characterization and particle combustion kinetics calculations, aiming to reveal the Pt-Pd synergistic effect and its carbon soot oxidation law. The results show that Pt-based catalysts doped with Pd can improve the catalyst dispersion, significantly increase the specific surface area, and reduce the activation energy and reaction temperature of carbon soot reactions, but excessive doping of Pd leads to the enhancement of the catalyst agglomeration effect, a decrease in the specific surface area, and an increase in the activation energy and reaction temperature of the carbon soot reaction. The specific surface area and pore capacity of the catalyst are the largest, and the activation energy of particle oxidation and the pre-exponential factor are the smallest (203.44 kJ∙mol−1 and 6.31 × 107, respectively), which are 19.29 kJ∙mol−1 and 4.95 × 108 lower than those of pure carbon soot; meanwhile, the starting and final combustion temperatures of carbon soot (T10 and T90) are the lowest at 585.8 °C and 679.4 °C, respectively, which are 22.1 °C and 20.9 °C lower than those of pure carbon soot.

Synergistic effect between amorphous ZrO2 modified support and Pd catalyst: Unveiling superlative sulfur resistance and exquisite catalytic hydrogenation performance

The presence of sulfides in the reaction system can seriously affect the stability and activity of the catalysts. In this paper, we compare the impact of introducing varying amounts of the metal oxide ZrO2 on the hydrogenation activity and sulfur resistance of Pd-based catalysts. The study examined the effect of calcination temperature for catalysts and various organic sulfide types on their catalytic performance. We employed multiple techniques to characterize the catalysts, including physical adsorption, TEM, XRD, XPS, H2-TPD, NH3-TPD, and Py-IR. The results revealed that the catalysts achieved 99.9 % conversion and exhibited 99.5 % selectivity towards 4-ethyltoluene when the Pd and Zr molar ratio was 1:5. Furthermore, they could withstand the presence of toxicants for over 10 cycles. The main reason for the difference in activity and stability between catalysts lies in introducing ZrO2 as a promoter. This introduction increases the number of acidic sites and enhances the electronic effect, thereby facilitating the cleavage of H2 by Pd0. The synergistic effect between Pd and ZrO2 decreases the strength of S-Me, impedes sulfide adsorption, and improves the sulfur resistance stability of the catalyst. This work demonstrates that ZrO2-modified Pd-based catalysts have great potential in the anti-sulfur system of olefin hydrogenation.

Low detection based on Pd Pt /In2O3 nanospheres for rapid hydrogen detection

Semiconductor gas sensors still have limitations in realizing rapid hydrogen measurement in lower hydrogen concentration environments. Therefore, in this paper, In2O3 cloud-like spherical hydrogen detection sensing materials with different Pd and Pt ratio loading were successfully prepared using the water bath method. The In2O3 sensing materials modified with noble metals Pd and Pt were designed for the rapid detection of hydrogen at 400 ppb with good selectivity under mixed gas components. The crystalline phase, morphology, and chemical composition of the prepared Pd and Pt-loaded In2O3 samples were analyzed using characterization techniques. The gas-sensing results showed that the In2O3 gas-sensing sensor with a Pd and Pt ratio loading of 1–2 had stronger H2 sensing performance at the optimum operating temperature (350°C). The response time and recovery time of In2O3 loaded with the opinion ratio at 350℃ and 400 ppb were 1 s and 15 s. The low detection limit was 400 ppb, with good repeatability and long-term stability. Finally, the enhanced gas sensitization mechanism of the In2O3 gas sensor loaded with Pd and Pt for H2 was discussed.

Synergistic effect of PDA and PVP on nanosized Pd doped graphite felt/Ni electrode for promoting the electrocatalytic degradation of 2,4- dichlorophenoxyacetic acid

Reducing the mass transfer barrier for the diffusion of water and pollutants to Pd sites is an important measure to achieve efficient degradation of chlorinated organic compounds. Herein, a simple electroless deposition method for preparing a superhydrophilic nanosized Pd-loaded graphite felt/Ni electrode with the aid of the dispersibility of polyvinylpyrrolidone (PVP) and adhesiveness of polydopamine (PDA) is proposed. The GF/Ni/PDA/Pd-PVP electrode exhibited high electrocatalytic activity toward 2,4-dichlorophenoxyacetic acid (2,4-D) under the optimized conditions, namely degradation and dechlorination efficiencies of 90.5% and 88.53%, respectively, corresponding to 39% higher than that on the GF/Ni/Pd electrode. Experimental results revealed that PDA and PVP doping enhanced the hydrophilicity of the electrode, promoted the dispersibility of Pd nanoparticles (NPs), and the formation of Pd (111) and Ni (111) crystal facets. Compared to the electron-deficient PVP, the appropriate electron-donating ability of PDA promoted the formation of a suitable ratio of electro-deficient and electron-rich Pd, thus enhancing the production of Hads* and C-Cl scission. Moreover, theoretical calculation indicated that the doping of PDA and PVP optimized the adsorption energies of 2,4-D, Hads*, and the main dechlorination product PA, which was obtained via 4-electron transfer via Hads*. Therefore, this study provides a simple and feasible way to fabricate an efficient cathode for 2,4-D dechlorination.

Voltammetric quantification of H:Pd ratio complicated by α↔β phase transition in PdHx: Electrodes with low Pd loadings

The Pd hydride (PdHx) is a typical system to study the fundamentals of solute intercalation and phase transformations or to determine the effect of strain on the rate of electrocatalytic reactions. A crucial methodological aspect, however, involves quantitatively determining the hydrogen-to-palladium atomic ratio (H:Pd) under experimental conditions where various incidental contributions to the total electrode charge are comparable to the charge spent for H adsorption/absorption and desorption. This is the case for electrodes with relatively low (dozens of μg/cm2) loadings of Pd on various porous supports, typically used to study the oxidation of small organic molecules or the reduction of oxygen in acidic or alkaline fuel cells. Ultra-low Pd loadings (often in the range of a few μg/cm2) are also typical for Pd nanoparticles on smooth supports, which are commonly considered as model systems for in situ structural studies of hydrogen sorption. To determine accurately the H content in Pd particles, we propose a technique based on analysis of charge disbalance at anodic and cathodic scans of a cyclic voltammogram, and also address the contribution of adsorbed H. To illustrate the possibilities and limitations of this technique, we present the voltametric study of thin electrodeposited Pd layers on glassy carbon and of a carbon-supported Pd catalyst.

Biosynthesis Parameters Control the Physicochemical and Catalytic Properties of Microbially Supported Pd Nanoparticles.

The biosynthesis of Pd nanoparticles supported on microorganisms (bio-Pd) is achieved via the enzymatic reduction of Pd(II) to Pd(0) under ambient conditions using inexpensive buffers and electron donors, like organic acids or hydrogen. Sustainable bio-Pd catalysts are effective for C-C coupling and hydrogenation reactions, but their industrial application is limited by challenges in controlling nanoparticle properties. Here, using the metal-reducing bacterium Geobacter sulfurreducens, it is demonstrated that synthesizing bio-Pd under different Pd loadings and utilizing different electron donors (acetate, formate, hydrogen, no e- donor) influences key properties such as nanoparticle size, Pd(II):Pd(0) ratio, and cellular location. Controlling nanoparticle size and location controls the activity of bio-Pd for the reduction of 4-nitrophenol, whereas high Pd loading on cells synthesizes bio-Pd with high activity, comparable to commercial Pd/C, for Suzuki-Miyaura coupling reactions. Additionally, the study demonstrates the novel synthesis of microbially-supported ≈2nm PdO nanoparticles due to the hydrolysis of biosorbed Pd(II) in bicarbonate buffer. Bio-PdO nanoparticles show superior activity in 4-nitrophenol reduction compared to commercial Pd/C catalysts. Overall, controlling biosynthesis parameters, such as electron donor, metal loading, and solution chemistry, enables tailoring of bio-Pd physicochemical and catalytic properties.

Pd-Isatin-Schiff base complex supported on graphene oxide as a catalyst for the Sonogashira cross-coupling reaction

The study reports on the synthesis and characterization of palladium-Isatin-Schiff base complex supported on graphene oxide (Pd-Isatin-Schiff base@rGO), as well as its application in the Sonogashira cross-coupling reaction. The catalyst was easily prepared by a simple method through modification of GO with (3-aminopropyl) triethoxysilane (APTES) as a linker. The reaction of free amine groups with isatin allowed the synthesis of Isatin-Schiff base@rGO. The subsequent complexation/immobilization of palladium provided the Pd-Isatin-Schiff base@rGO nanocomposite with a Pd(II) to Pd(0) ratio=1.17. The prepared Pd-Isatin-Schiff base@rGO nanocomposite was fully characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), CHN elemental analysis, scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), thermogravimetric analysis (TGA), high-resolution transmission electron microscope (HRTEM), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma optical emission spectroscopy (ICP-OES) to establish its structure and composition. This heterogeneous nanocomposite catalyst was found very efficient for the cross-coupling reaction of an alkyne and an aryl halide, generating a high yield of coupling products (80–95 %) after 1 h. A reusability study revealed that the Pd-Isatin-Schiff base@rGO composite could be recycled for six consequent cycles without significant loss of its activity. However, after six cycles, the yield of 1,2-diphenylethyne as the coupling product decreased slightly from 93 % to 85 % and a decrease 8 wt.% in the Pd content was observed using ICP analysis.

P-doped RuPd nanoparticles anchored on Y2Ru2-xPdxO7 pyrochlore oxide surface as oxygen evolution and reduction electrocatalysts for Zn-air battery

Metal-air battery technology is the most promising green technology. However, the sluggish kinetics of the oxygen evolution/reduction reaction (OER and ORR), which are key reactions in air cathode, must be improved. In this study, Pd substitution was introduced into Y2Ru2O7 pyrochlore oxides and the ratio of Pd was varied (YRPO-x). Then, P-doped RuPd nanoparticles were synthesized on Pd-substituted YRPO pyrochlore (YRPO/RuPd-P) by an in situ exsolution process to create bifunctional electrocatalysts facilitating both reactions. The uniquely designed YRPO/RuPd-P catalyst exhibited the OER overpotential and Tafel slope (Ej10 = 232 mV; Tafel slope = 37.1 mV/dec). Furthermore, YRPO/RuPd-P shows an E1/2 of 0.82 V, indicating superior ORR activity. This was further investigated by applying in a unit-cell battery system, which showed an outstanding power density (163 mW/cm2) and robust charge–discharge stability. This study proposes a novel design strategy for bifunctional electrocatalysts.

Ultrasmall metal alloy nanozymes mimicking neutrophil enzymatic cascades for tumor catalytic therapy

Developing strategies that emulate the killing mechanism of neutrophils, which involves the enzymatic cascade of superoxide dismutase (SOD) and myeloperoxidase (MPO), shows potential as a viable approach for cancer therapy. Nonetheless, utilizing natural enzymes as therapeutics is hindered by various challenges. While nanozymes have emerged for cancer treatment, developing SOD-MPO cascade in one nanozyme remains a challenge. Here, we develop nanozymes possessing both SOD- and MPO-like activities through alloying Au and Pd, which exhibits the highest cascade activity when the ratio of Au and Pd is 1:3, attributing to the high d-band center and adsorption energy for superoxide anions, as determined through theoretical calculations. The Au1Pd3 alloy nanozymes exhibit excellent tumor therapeutic performance and safety in female tumor-bearing mice, with safety attributed to their tumor-specific killing ability and renal clearance ability caused by ultrasmall size. Together, this work develops ultrasmall AuPd alloy nanozymes that mimic neutrophil enzymatic cascades for catalytic treatment of tumors.

How and when do Pt- and Pd-semimetal minerals crystallize from saturated sulfide liquids?

Platinum and Pd-arsenides, antimonides, tellurides, bismuthinides, and sulfides are the major hosts of Pt and Pd in magmatic and hydrothermal Cu-Ni-sulfide ores. Textural relationships among such minerals in nature often provide contradictory messages about the mechanism and timing of their formation. To know how and when Pt and Pd mineral phases crystallize from sulfide-saturated liquids and how their compositions and textures evolve during cooling, we undertook controlled cooling experiments in evacuated silica tubes. A Cu-Ni-Fe sulfide mixture, similar in composition to the average Merensky Reef sulfide magma, was charged (in a 9:1 wt.% proportion) with one of the PtAs2, PtTe2, PtSb2, PtBi2, PdAs2, PdTe2, PdSb, and PdBi2 compounds, heated to 1,100°C, and slowly cooled (15°C/day) to room temperature. The run products were sampled at 950°C, 750°C, and 25°C by quenching the silica tubes in water. The results show that Pt formed stable phases with As, Te, and Sb above 950°C and with Bi and S below 750°C. The Pt phases were found mostly in the decomposed intermediate solid solution (ISS), and all the phases survived to 25°C with no compositional changes. At 950°C, Pd formed arsenide, telluride, and antimonide immiscible melts that coexisted with monosulfide solid solution (MSS) and sulfide melt. The composition of the Pd-semimetal melt droplets changed during cooling by equilibration with the host sulfide. Palladium mineral phases formed at temperatures below 750°C directly from the immiscible semimetal-rich melts where they kept the rounded shapes of the melt droplets. Ni-sulfarsenides preceded the formation of Pd arsenides. No Ni tellurides, antimonides, or bismuthinides formed in any of the systems, implying that their formation requires higher semimetal/Pt + Pd ratios. The decomposition of MSS and ISS to base metal sulfides led to significant textural changes in Pt and Pd mineral grains. The compositions of Pt and Pd phases are inherited from the magmatic stage, and their textures are low-temperature (&amp;lt;450°C) features.

Performance and microbial response to nitrate nitrogen removal from simulated groundwater by electrode biofilm reactor with Ti/CNT/Cu5-Pd5 catalytic cathode.

To enhance the removal of nitrate nitrogen (NO3 - -N) in groundwater with a low C/N ratio, electrocatalytic reduction of NO3 - -N has received extensive attention since its electrons can be directly produced in situ while simultaneously providing a clean electronic donor of hydrogen for denitrifying bacteria. In this study, Ti/CNT/CuPd bimetallic catalytic electrodes with different copper-palladium (CuPd) ratios were prepared by electrodeposition onto carbon nanotube (CNT) using titanium (Ti) plates. The results showed that the NO3 - -N conversion rate by Ti/CNT/Cu5-Pd5 electrode was the highest (53.60%) compared with other CuPd electrode ratios because of the combined role of the copper's high NO3 - -N catalytic activity and the palladium's high N2 selectivity. A new type of electrode biofilm reactor (EBR) with Ti/CNT/Cu5-Pd5 cathode, biochar substrate was constructed to explore the removal ability of NO3 - -N in simulated low C/N groundwater. When the influent NO3 - -N concentration was 30 mg/L, under the condition of a 30 mA electronic current and hydraulic retention time (HRT) of 12 h, the removal rate of NO3 - -N could reach as high as 78.1 ± 1.2%, and the N2 conversion rate was 99.7%. The horizontal distribution of microbial communities in EBR showed that the denitrification capacity was significantly improved through the electrochemical catalytic reduction of the Ti/CNT/Cu5-Pd5 cathode and the supply of the hydrogen electron donor to autotrophic denitrogenerating microbes such as Anaerobacillus, Thauera, and Hydrophaga. This study provides a new bimetallic catalytic cathode to enhance the removal of NO3 - -N in groundwater with a low C/N ratio. PRACTITIONER POINTS: The Cu5Pd5/CNTs/Ti electrode is beneficial to the adsorption and reduction of NO3 - -N to N2 . The production of hydrogen electron donors by cathode promoted nitrogen degradation. Activated electrodes together with denitrifying microorganisms contributed to the improved N removal rate.

Bimetallic Au–Pd nanoparticles decorated electrospun spinel CoFe2O4 nanostructures as efficient electrocatalysts for ethanol fuel oxidation in alkaline media

Spinel-based materials are promising candidates as electro-catalysts for the oxidation of alcohol fuels. In the present study, electrospun CoFe2O4 spinel nanostructures were prepared by electrospinning technique and the subsequent thermal treatment processes. Then, the bimetallic Au–Pd–CoFe2O4 composite as electro-catalysts were synthesized by precipitation method. The surface morphology, composition and structure of the resulting composite nanostructures were studied by FE-SEM, EDS, TEM, XPS, XRD and FT-IR. The catalytic performance of resultant composite has been examined in ethanol electro-oxidation reactions under alkaline conditions. The effect of different Au:Pd ratios on the electrocatalytic performance of Au–Pd–CoFe2O4 composite nanostructures for ethanol oxidation was evaluated. The synthesized composite Au–Pd–CoFe2O4 (APCo22) illustrates a superior ethanol oxidation activity in comparison to other electrocalysts, and the peak current of this spinel-type electro-catalysts is 9.89 times that of Pd–CoFe2O4 with a scan rate of 50 mVs−1, which is due to the synergistic effect of Au and Pd on CoFe2O4. Furthermore, the remarkable electrochemical property can be due to the production of OH−, which leads to the species present on the surface of the electro-catalysts during the activation process.

Efficient formaldehyde sensor based on PtPd nanoparticles-loaded nafion-modified electrodes

The noble metal-based electrochemical sensor design for efficient and stable formaldehyde(FA) detection is important ongoing research. In this paper, PtPd/Nafion/GCE is prepared by electrochemical cyclic voltammetry deposition method based on electrodepositing nanostructured platinum (Pt)-palladium (Pd) nanoparticles in Nafion film-coated glassy carbon electrode (GCE). The influence of deposition parameters and chemical composition (atomic ratio of Pt and Pd) on the electrochemical behaviour of PtPd/Nafion/GCE has been investigated. PtPd/Nafion/GCE displays a remarked electrocatalytic activity for the oxidation of FA and exhibits a linear relationship in the range of 10–5000 μM, with a detection limit of 3.3 μM in 0.1 M H2SO4 solution. It is proved that the detection performance of PtPd/Nafion/GCE electrode is valuable for further application with low detection limit, wide linear range, favourable selectivity and high response.

Electrooxidation of methanol and ethanol catalyzed by high-performance three-dimensional graphene-supported PdM (Co, Cu) binder-free electrode

PdM/RGN (M = Co, Cu) self-supporting composite electrodes were synthesized via a simple two-step spontaneous reduction process using Ni foam as the substrate and reduced graphene oxide as support layer. The composites were characterized using X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. Cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy were performed to study the electrocatalytic activities of the prepared electrodes for methanol and ethanol oxidation. The performances of PdM/RGN for methanol and ethanol oxidation increased and then decreased as the atomic ratio of Pd to M (Co, Cu) increased. The Pd6Co1/RGN and Pd6Cu1/RGN electrodes exhibited markedly superior catalytic activity and long-term stability. The peak current densities of Pd6Cu1/RGN and Pd6Co1/RGN electrodes reached 0.36 and 0.29 A/cm2 for methanol electrooxidation and which reached 0.8 and 0.5 A/cm2 for the ethanol electrooxidation, respectively. This excellent performance is owing to the three-dimensional structure of nickel foam, the improving specific surface area and the synergistic effect between Pd and M.

Easily hydroxylated PtxPd1-x-TiO2 nanotube arrays: An energetic Schottky photocatalyst for synergistically boosted degradation of Microcystin-LR

The metal co-catalyst-based photocatalytic oxidation technology provides a promising approach to eliminate contaminants from water. However, the applicability of these catalysts often suffer from severe carrier recombination and high activation energy barriers of reactive oxygen species (ROS). Herein, self-supporting TiO2 nanotube arrays were engineered with PtPd atom clusters having atomically controlled molar ratio, assembling a dynamic Mott-Schottky catalyst for photocatalytic removal of Microcystin-LR, a toxin produced by cyanobacteria. The separation of photogenerated carriers and the creation of reactive oxygen species (ROS) are optimized by regulating electronic construction via tailoring the Pd ratio in PtPd atom clusters (ca. 4.6 nm in size). The exciton lifetime of the optimum Pt0.9Pd0.1-TiO2 is shortened from 2.51 ns on pure TiO2 to 1.16 ns, and the Gibbs free energy for forming hydroxyl radicals (•OH) varies from −0.826 eV (pure TiO2) to −2.576 eV, powering plentiful •OH when Pt0.9Pd0.1-TiO2 illuminated under solar lights. The kinetic constant of Pt0.9Pd0.1-TiO2 for MC-LR removal is 12.7 times higher than that of the pristine TiO2, presenting exceptional photocatalytic capacity in turning Microcystin-LR into harmless chemicals.

Co-treatment of diamond-wire-saw silicon kerf and spent automotive catalysts for simultaneous recovery of PGMs, REEs, Zr, and high-purity Si

Spent automotive catalysts (SACs) and diamond-wire-saw silicon kerf (DWSSK) are classified as hazardous wastes. Currently, the two wastes are treated separately using unrelated approaches. More than two independent approaches are required to recover platinum group metals (PGMs), Zr and rare earth elements (REEs) from SACs, and recover Si from DWSSK, which is time-consuming and laborious. In this study, a new approach was proposed to co-treat the two wastes based on the concept of using waste treats waste: using DWSSK (∼89.85 wt% Si) as a new metal collector to extract PGMs, REEs, and Zr simultaneously from SACs to obtain a Si-VM alloy (VM: valuable metal); meanwhile, using the carrier of SACs to form molten slag to eliminate the main impurity, O, from DWSSK. The largest recovery ratios of Pd, Rh, Zr, Ce, La, and Nd from SACs were 99.50 ± 0.10%, 99.14 ± 0.14 %, 96.19 ± 0.76%, 67.18 ± 4.57%, 61.24 ± 4.93% and 47.65 ± 7.27%, respectively, and the largest removal ratio of O from DWSSK was 99.96%. After smelting, the Si-VM alloy was separated into high-purity Si and VM-containing acid solutions via acid leaching. The leaching ratios of Pd, Rh, Ce, La, Nd, and Zr were 99.78%, 98.15%, 99.93%, ∼100%, 99.76% and 99.98%, respectively. The purity of Si was upgraded from 89.85 wt% (in DWSSK) to 99.98 wt% after acid leaching. The new approach proposed in this study is considered more environmentally friendly and cost-effective than the regular approaches that treat the two wastes separately.