Potential Catalyst Research Articles

Alkaline modified Zr-loading on nanosheet zeolite towards production of γ-valerolactone from levulinic acid through catalytic transfer hydrogenation

A self-pillared nanosheet ZSM-5 zeolite (SP) loading Zr catalyst is prepared for conversion of levulinic acid (LA) to produce γ-valerolactone (GVL). The hierarchical pore by nanosheet aggregates promotes Zr dispersion with establishment of strong interaction between Zr and zeolite. Moreover, Na ions are introduced to modify the chemical environment of Zr on nanosheet zeolite (Zr/NaSP). In catalytic transfer hydrogenation of LA using isopropanol as H-donor, uniformly dispersed Zr species on SP zeolite is conducive for both conversion of LA as well as production of GVL, in comparison with samples using conventional microporous ZSM-5 as supports (Zr/CZ). More importantly, different from protonated zeolite sample (Zr/HSP), the introduction of alkali sites could attract protons in hydroxyl groups of isopropanol, which accelerates the generation rates of GVL. The as-designed Zr/NaSP catalyst delivers GVL generation rates of 31.9 mmol·g-1·h-1, which provides a potential catalyst for GVL production.

Quiet environments and the intentional practice of silence: Toward a new perspective in the analysis of silence in organizations

AbstractWhile nonspeech communication and “metaphorical” silence (in opposition to voice) have benefited from a considerable academic attention, less is known about quiet environments and the intentional practice of silence. We theorize these silences as potential catalysts of internal and collective reflection. Such silences can strongly impact individual and organizational processes and outcomes, notably in the workplace. The meaning, valence, and effects of these silences are highly context- and perspective-dependent. By characterizing and studying these silences and their effects, we show how they are functional or dysfunctional to individuals or organizations. These silences can notably serve as emotion regulators and generate an environment favorable to individual and collective decision making. Examining what is lost by individuals and organizations due to a lack of these silence and what can be gained with a better harnessing of their power is promising.

Detection and Characterization of Hydride Ligands in Copper Complexes by Hard X-Ray Spectroscopy.

Transition metal complexes, particularly copper hydrides, play an important role in various catalytic processes and molecular inorganic chemistry. This study employs synchrotron hard X-ray spectroscopy to gain insights into the geometric and electronic properties of copper hydrides as potential catalysts for CO2 hydrogenation. The potential of high energy resolution X-ray absorption near-edge structure (HERFD-XANES) and valence-to-core X-ray emission (VtC-XES) is demonstrated with measurement on Stryker's reagent (Cu6H6) and [Cu3(μ3-H)(dpmppe)2](PF6)2 (Cu3H), alongside a non-hydride copper compound ICu(dtbppOH) (Cuy-I). The XANES analysis reveals that coordination geometries strongly influence the spectra, providing only indirect details about hydride coordination. The VtC-XES analysis exhibits a distinct signal around 8975 eV, offering a diagnostic tool to identify hydride ligands. Theoretical calculations support and extend these findings by comparing hydride-containing complexes with their hydride-free counterparts.

The Surface Confinement of FeO Assists in the Generation of Singlet Oxygen and High-Valent Metal-Oxo Species for Enhanced Fenton-Like Catalysis.

Transition metal compounds (TMCs) have long been potential candidate catalysts in persulfate-based advanced oxidation process (PS-AOPs) due to their Fenton-like catalyze ability for radical generation. However, the mechanism involved in TMCs-catalyzed nonradical PS-AOPs remains obscure. Herein, the growth of FeO on the Fe3O4/carbon precursor is regulated by restricted pyrolysis of MIL-88A template to activate peroxymonosulfate (PMS) for tetracycline (TC) removal. The higher FeO incorporation conferred a 2.6 times higher degradation performance than that catalyzed by Fe3O4 and also a higher interference resistance to anions or natural organic matter. Unexpectedly, the quenching experiment, probe method, and electron paramagnetic resonance quantitatively revealed that the FeO reassigned high nonradical species (1O2 and FeIV═O) generation to replace original radical system created by Fe3O4. Density functional theory calculation interpreted that PMS molecular on strongly-adsorbed (200) and (220) facets of FeO enjoyed unique polarized electronic reception for surface confinement effect, thus the retained peroxide bond energetically supported the production of 1O2 and FeIV═O. This work promotes the mechanism understanding of TMCs-induced surface-catalyzed persulfate activation and enables them better perform catalytic properties in wastewater treatment.

Integration of a Bismuth-Based Tris-Mononuclear Complex with 2D Functional Materials for Highly Efficient and Durable Aqueous Electrocatalytic Hydrogen Evolution.

The eminence of transitioning from traditional fossil fuel-based energy resources to renewable and sustainable energy sources is most evidently crucial. The potential of hydrogen as an alternative energy source has specifically focuses the electrocatalytic water splitting (EWS) as a promising technique for generating hydrogen. Development of efficient electrocatalysts to facilitate the EWS process while rationalizing the limitations of noble metal catalysts like platinum has become one of the daunting tasks. Consequently, porous functional materials such as metal complexes (MCs) and graphene oxide (GO) can act as potential catalysts for EWS. Therefore, a composite of GO and a mononuclear bismuth metal complex is synthesized through in situ facile synthesis, which is further utilized as an efficient electrocatalyst for the hydrogen evolution reaction (HER). Several potential electrocatalytic MC@GO composite (BMGO-3,5,7) materials were prepared with compositional variation of GO (3, 5, and 7 wt %). The experimental results demonstrate that the BMGO5 composite exhibits excellent HER activity with a low overpotential value of 105 mV at 10 mA cm-2 and a low Tafel slope of 44 mV dec-1 in 1 M KOH solution. Furthermore, a comprehensive investigation on the potentiality of the BMC-GO composite for hydrogen evolution from river water splitting was performed in order to address the issue of freshwater depletion. Inclusion of a mononuclear MC for facile synthesis of functional GO-based efficient electrocatalyst material is very scanty in the literature. This unique approach could assist future research endeavors toward designing efficient electrocatalysts for sustainable renewable energy generation. This is one of the first of its kind, where mononuclear MCs were utilized to develop GO-based functional composite materials for efficient electrocatalysis toward sustainable renewable energy generation.

What Are the Challenges and Opportunities in to Improve Human Capital and Value Added in Cambodia's Garment Industry for the Purpose of Poverty Reduction?

In pursuit of a comprehensive poverty reduction strategy for Cambodia, this paper begins with an analysis of the value ladder of Cambodia's garment industry. This paper argues for a shift from the bottom of the ladder, a labor-intensive economy, to more advanced sectors involving technology, design, and skilled labor as a potential catalyst for poverty reduction progress. Furthermore, this paper emphasizes that Cambodia's opportunity to lift its position from the value ladder hinges on the augmentation of human capital, primarily through strategic investments in education. Subsequently, the paper delves into the challenges confronting the Cambodian government in its efforts to address poverty. Drawing inspiration from the successful Conditional Cash Transfer (CCT) programs implemented in Mexico (Oportunidades) and Brazil (Bolsa Famlia) to tackle similar poverty-related challenges, this paper examines their outcomes. It evaluates their practicality within the Cambodian context as a policy recommendation.

Association between pediatric postoperative delirium and regional cerebral oxygen saturation: a prospective observational study

BackgroundPostoperative delirium (POD) represents a prevalent and noteworthy complication in the context of pediatric surgical interventions. In recent times, a hypothesis has emerged positing that cerebral ischemia and regional cerebral oxygen desaturation might serve as potential catalysts in the pathogenesis of POD. The primary aim of this study was to methodically examine the potential relationship between POD and regional cerebral oxygen saturation (rSO2) and to assess the predictive and evaluative utility of rSO2 in the context of POD.MethodsThis prospective observational study was conducted at the Children’s Hospital, Zhejiang University School of Medicine, Zhejiang, China, spanning the period from November 2020 to March 2021. The research cohort comprised children undergoing surgical procedures within this clinical setting. To measure rSO2 dynamics, cerebral near-infrared spectroscopy (NIRS) was used to monitor rSO2 levels both before and after surgery. In addition, POD was assessed in the paediatric patients according to the Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM-5) criteria. The analysis of the association between the rSO2 index and the incidence of POD was carried out through the application of either the independent samples t-test or the nonparametric rank-sum test. To ascertain the threshold value of the adjusted rSO2 index for predictive and evaluative purposes regarding POD in the pediatric population, the Receiver Operating Characteristics (ROC) curve was employed.ResultsA total of 211 cases were included in this study, of which 61 (28.9%) developed POD. Participants suffering delirium had lower preoperative rSO2mean, lower preoperative rSO2min, and lower postoperative rSO2min, higher ∆rSO2mean, higher amount of ∆rSO2mean, lower ∆rSO2min (P < 0.05). Preoperative rSO2mean (AUC = 0.716, 95%CI 0.642–0.790), ∆rSO2mean (AUC = 0.694, 95%CI 0.614–0.774), amount of ∆rSO2mean (AUC = 0.649, 95%CI 0.564–0.734), preoperative rSO2min (AUC = 0.702, 96%CI 0.628–0.777), postoperative rSO2min (AUC = 0.717, 95%CI 0.647–0.787), and ∆rSO2min (AUC = 0.714, 95%CI 0.638–0.790) performed well in sensitivity and specificity, and the best threshold were 62.05%, 1.27%, 2.41%, 55.68%, 57.36%, 1.29%.ConclusionsThere is a close relationship between pediatric POD and rSO2. rSO2 could be used as an effective predictor of pediatric POD. It might be helpful to measure rSO2 with NIRS for early recognizing POD and making it possible for early intervention.

The Application of Pandan and Soybean Extracts on the Biosynthesis of Tin Oxide Nanoparticles

Development of benign and efficient approaches towards the replacement of the conventional methods for producing SnO2 nanoparticles (SnO2 NPs) has begun in which a biosynthesis process has been introduced. This study utilizes biomolecules, specifically the flavonoids and carbohydrate groups in pandan and soybean extracts. The biosynthesized nanoparticles underwent characterization through relevant spectroscopies. Fourier transform infrared (FTIR) analysis revealed the absorption bands of SnO2 and Sn-O-Sn groups, with the complete disappearance of peaks associated with untreated pandan and soybean. X-ray Diffraction (XRD) indicated the formation of tetragonal structure in SnO2 NPs with primary peaks at 27o, 34o, and 51o. Additionally, UV-Visible diffuse reflectance spectroscopy (DRS) yielded band gap values of 4.86 and 3.45 eV for SnO2 NPs derived from pandan and soybean, respectively. In summary, the application of biosynthesized SnO2 NPs as a potential heterogeneous catalyst for purifying dye-polluted water through a photocatalytic process is highlighted.

High-Throughput screening of metal nitrides for electrochemical nitrogen reduction

Metal nitrides have garnered considerable attention in the context of nitrogen reduction reactions (NRR) due to their rich lattice nitrogen and abundant nitrogen vacancies to activate N2. However, the identification of suitable metal nitrides with superior stability, activity, and selectivity (vs. hydrogen evolution reaction, HER) for electrochemical NRR under rigorous isotope labeling experiments remains a perplexing challenge in experiments. In this study, we implemented a systematic screening protocol to assess the electrochemical stability and efficiency of various metal nitrides for NRR by high-throughput density functional theory calculations, aiming to search out promising metal nitride catalysts. Through a set of predetermined criteria, a subset of 6 candidates emerges as the most promising metal nitrides for NRR from a pool of 668 metal nitrides sourced from the Materials Project Database, all of which catalyze NRR following the Mars-van Krevelen pathway. Importantly, based on the analysis of these candidates, the unique structural property (i.e., four(or three)-coordinate lattice nitrogen) and energy descriptor (i.e., the formation energy of the lattice nitrogen vacancy is around 2.1 eV) of potential metal nitrides for electrochemical NRR were extracted, which could be used as the direction to rationally design metal nitride catalyst. This research not only serves as a valuable guide for experimental investigations into potential metal nitrides for NRR, but also provides an efficient method for high-throughput screening of potential catalysts for other electrochemical reactions.

Low-temperature activated porous carbon with functional groups derived from waste tea powder as a potential catalyst for CO2 fixation into cyclic carbonates

The globe is currently confronted with two main environmental problems: environmental solid waste and greenhouse gases. Thus, it is urgent to mitigate these issues and convert them into value-added products. In this context, this work demonstrated the mitigation of two global issues with a single approach. This work established a facile process for a hierarchical porous carbon from abundant bio-waste, such as waste tea powder, and employed it as a heterogeneous catalyst for CO2 fixation into cyclic carbonate. Derived porous carbon catalysts, WTC-1 (Waste tea carbon), WTC-2, AWTC-2-400 (Activated waste tea carbon), AWTC-2a-400, AWTC-2-600, and AWTC-2-800, were produced without the use of solvent by acid-free washing and KOH-free activation. These WTC catalysts were characterized by several standard techniques: XRD, FTIR, XPS, SEM, BET, and TPD. Among the low-temperature activated carbon catalysts, AWTC-2a-400 with potassium-based salt, KI exhibited excellent conversion of propylene oxide (98 %) and ≥99 % selectivity of propylene carbonate without solvent under mild conditions of 2.5 MPa, 120 °C, and 2 h. It was observed that the catalytic activity of the WTC catalyst was attributed to the presence of Lewis acidic and basic sites, CaO/CaCO3, MgO, –COOH/OH, and –NH, which are capable of activating the CO2 molecule. Further, the developed catalytic system (AWTC-2a-400/KI) demonstrated superior catalyst versatility for various epoxides under optimized conditions. Moreover, AWTC-2a-400 showed good stability and reusability. Importantly, all reactions were conducted on a gram scale, and the proposed catalyst was effective, which might be favorable for future industrial applications.

Spectroscopic monitoring of polyurethane-based nanocomposite as a potential catalyst for the reduction of dyes

In this study, AgNPs-loaded polyurethane-sodium alginate (PU-S/Alg) composite polymers were prepared by precipitation polymerization and in-situ reduction method. Their catalytic potential was evaluated for the reduction of methyl orange (MO), brilliant blue (BB), Rhodamine B (RhB), 4-nitroaniline (4-NA), and 4-nitrophenol (4-NP). Successful preparation of samples was confirmed by UV–Visible spectrophotometry (UV–Visible), Fourier transform infrared (FTIR), and Scanning electron microscopy (SEM) analysis. During the catalytic study, the value of kapp for the reduction of MO in the presence of NaBH4 and catalyst was found 0.488 min−1 while, in the presence of NaBH4 and catalyst alone, were found as 0.9 × 10-4 and 0.8 × 10-5 min−1, respectively which indicates the role of catalyst in making the reaction speedy. The value of kapp for the reduction of BB, RhB, 4-NA, and 4-NP was found as 0.764, 0.475, 0.212 and 0.757 min−1, respectively. Simultaneous reduction of dyes induced a decreased reaction completion time under the same reaction conditions. A slight increase in the value of kapp for the catalytic reduction of MO was also observed when reactions were performed in the presence of ionic media of different salts such as NaCl, KCl, CaCl2, and MnCl2. The rate of reduction of MO was increased with the increase in ionic strength of the medium. However, the presence of SDS (surfactant) in the reaction mixture induced the decreased activity of the catalyst and increased reaction completion time. The same value of kapp for the reduction of MO was observed in the case of freshly prepared and several days old nanocomposite catalyst. These results illustrate the stability and maintained catalytic potential of metal NPs for a prolonged time. Our reported catalyst also showed good potential for the treatment of dyes-polluted textile industry wastewater.

2D g-CN@Ni-bpy MOF nano-composite for photocatalytic activity

Ni-bpy MOF and g-CN@Ni-bpy MOF composite were fabricated by a one-pot solvothermal technique. The morphological and elemental composition was put forward by the study of PXRD, FT-IR, XPS, FE-SEM, EDS, HRTEM and UV-DRS. The as-synthesized nano-composite was effectively utilized as catalyst for Z-scheme degradation of Malachite green dye under natural sunlight. The g-CN@Ni-bpy MOF nano-catalyst caused degradation of 97.7 % of the dye within 45 min without the aid of any further additives. Furthermore, the mechanism of Z- scheme degradation over g-CN@Ni-bpy MOF was also investigated. From all this, it can be concluded that g-CN@Ni-bpy MOF is a potential catalyst for wastewater remediation.

Catalytic performance of modified carbon black on methane decomposition for hydrogen production.

Carbon-based catalysts catalyze methane decomposition to produce hydrogen is a very attractive technical route. Carbon black in carbon-based catalysts has the advantages of high catalytic activity, good stability and better tolerance to toxic impurities such as sulphur in the feedstock, which has become a hot topic of research for many scientists. In this work, the effect of heat treatment on the structural and surface properties of carbon blacks and their catalytic performance in hydrogen production from methane decomposition was investigated. A commercial carbon blacks N110 was selected to heat treatment with nitrogen or carbon dioxide atmosphere at 850 °C, respectively. The Raman spectrums indicated that the graphitization degree of modified carbon under two atmospheres were promoted with the treatment time increasing. BET results revealed that the specific surface area of the carbon black treated under carbon dioxide increased, while the specific surface area was unchanged for that of the carbon black treated under nitrogen. The catalytic test of the two modified carbon blacks for methane decomposition exhibited the almost same activity, which meant that the graphitization degree of carbon black is the key factor for methane decomposition rather than the specific surface area. It was suggested that highly graphitized carbon black could be used as the potential catalysts for hydrogen production from methane decomposition.

Precise Modulation of the Coordination Environment of Single Cu Site Catalysts to Regulate the Peroxymonosulfate Activation Pathway for Water Remediation.

Single atom site catalysts (SACs) with atomically dispersed active sites can be expected to be potential ideal catalysts for accurately modulating the persulfate activation pathway during the water remediation process because of their well-defined structure and the maximum metallic atom utilization. In this paper, a series of Cu SACs with different coordination environments were synthesized to elaborately regulate the peroxymonosulfate activation pathway in AOPs to clarify active species generation and transformation in water remediation. The degradation rate constants (kobs) of Cu-N2, Cu-N3, and Cu-N4 were 0.028, 0.021, and 0.015 min-1, respectively. Cu-N2 SACs exhibited a noticeable enhanced performance for bisphenol A (BPA) removal from water compared to that of the Cu-Nx SACs (x = 3, 4), accompanied by peroxymonosulfate (PMS) activation pathway variation. As shown by experimental and theoretical results, the PMS activation pathway was transformed from ROS to electron transfer with nitrogen coordination numbers decreasing from 4 to 2, which can be ascribed to the uneven charge distribution of Cu sites as well as upshifts in the d-band center, and thereby optimized electron transfer for PMS activation. Furthermore, the increasing nitrogen vacancies of single Cu site catalysts can also result in more unoccupied 3d orbitals of Cu atoms in SACs, thereby improving the intermediates' (PMS and BPA) adsorption-desorption process and BPA removal performance. These findings provided a beneficial approach for the coordination number regulation of SACs in water remediation.

Analyzing the Active Site and Predicting the Overall Activity of Alloy Catalysts.

As one of the potential catalysts, disordered solid solution alloys can offer a wealth of catalytic sites. However, accurately evaluating their activity localization structure and overall activity from each individual site remains a formidable challenge. Herein, an approach based on density functional theory and machine learning was used to obtain a large number of sites of the Pt-Ru alloy as the model multisite catalyst for the hydrogen evolution reaction. Subsequently, a series of statistical approaches were employed to unveil the relationship between the geometric structure and overall activity. Based on the radial frequency distribution of metal elements and the distribution of ΔGH, we have identified the surface and subsurface sites occupied by Pt and Ru, respectively, as the most active sites. Particularly, the concept of equivalent site ratio predicts that the overall activity is highest when the Ru content is 20-30%. Furthermore, a series of Pt-Ru alloys were synthesized to validate the proposed theory. This provides crucial insights into understanding the origin of catalytic activity in alloys and thus will better guide the rational development of targeted multisite catalysts.

Machine Learning-Assisted Study of RENxC6-x-Doped Graphene as Potential Electrocatalysts for Oxygen Electrode Reactions.

In the application of renewable energy, the oxidation-reduction reaction (ORR) and oxygen evolution reaction (OER) are two crucial reactions. Single-atom catalysts (SACs) based on metal-doped graphene have been widely employed due to their high activity and high atom utilization efficiency. However, the catalytic activity is significantly influenced by different metals and local coordination, making it challenging to efficiently screen through either experimental or density functional theory (DFT) calculations. To address this issue, this study employed a combination of DFT calculations and machine learning (DFT-ML) to investigate rare earth-modified carbon-based (RENxC6-x) electrocatalysts. Based on computational data from 75 catalysts, we trained two ML models to capture the underlying patterns of physical properties and overpotential. Subsequently, the candidate catalysts were screened, leading to the discovery of four ORR catalysts, nine OER catalysts, and five bifunctional electrocatalysts, all of which were thoroughly validated for their stability. Lastly, by integrating the ML models with the SHAP analysis framework, we revealed the influence of atomic radius, Pauling electronegativity, and other features on the catalytic activity. Additionally, we analyzed the physicochemical properties of potential catalysts through DFT calculations. The revolutionary DFT-ML approach provides a crucial driving force for the design and synthesis of potential catalysts in subsequent studies.

CO2‐Steam Bi‐Reforming of Methane Over La1−xSrxNi0.8Zr0.2O3 Perovskite Catalysts to Generate Hydrogen Rich Syngas

AbstractThe present study proposes La and Sr‐containing La1−xSrxNi0.8Zr0.2O3 (x=0.1, 0.2, 0.4, 0.6, 0.8) perovskites as potential catalysts for bi‐reforming of methane (BRM) with CO2 and steam to produce hydrogen rich syngas. The catalysts were prepared by sol‐gel method and characterized using various techniques such as XRD, H2‐TPR, BET, CO2‐TPD and CHNS analysis. The characterization studies revealed that metal‐support interaction increased with the increase in the composition of Sr and the reduction behavior of Ni found to vary with the addition of Sr. The total energy calculations reveal that the addition of Sr to the LNZ system shirnks the volume due to low atomic and high ionic radii of Sr over La, which increases the total energy of system driving towards instability with increasing doping concentration of Sr. CO2‐TPD results suggest that a small amount of Sr can change the basicity of the support. The BRM activity results revealed that La0.8Sr0.2Ni0.8Zr0.2O3 perovskite is the most promising and active catalyst. The proposed catalysts are found to be advantageous w.r.t less carbon deposition due to the increased dispersion, small crystalline size, and required basicity of the support. The disclosed catalyst has shown excellent stability for a studied period of 100 h.

Imidazole-based organic polymer frameworks as metal- and halogen-free heterogeneous platforms for efficient CO2 cycloaddition

Developing effective metal- and halogen-free heterogeneous catalysts for the CO2 cycloaddition remains a challenge. In this study, novel imidazole-based hyper-crosslinked polymers (HCP-BZ, HCP-BP and HCP-TBZ) with abundant N sites were constructed via a one-pot polymerization, and employed as heterogeneous catalysts for the CO2 cycloaddition reaction. The special skeletal pore structure with abundant hierarchical pore structures and uniformly distributed active sites were demonstrated by various characterization technologies. The optimal HCP-TBZ(16:1) exhibits a good CO2 selective adsorption performance with a CO2 adsorption capacity of 2.23 mmol/g and CO2/N2 adsorption selectivity of 41 at 273 K and 0.1 MPa. Additionally, the resulting catalyst HCP-TBZ(16:1) achieves an excellent catalytic performance with 96 % yield and 99 % selectivity without metal, halogen, cocatalyst and solvent additions (120 °C, 1.0 MPa CO2, 5 h). Moreover, the HCP-TBZ(16:1) also exhibits a satisfactory catalytic activity under the mild conditions (70 °C, 1.0 MPa CO2), and can effectively catalyze the cyclic carbonate preparation from the dilute CO2 (15 %CO2/85 %N2). The comparable catalytic activity and the determined structural stability, reusability and universality make the prepared imidazole-based HCPs a potential heterogeneous catalyst candidate for the CO2 cycloaddition. This study will provide some guidance for developing metal-free and halogen-free CO2 adsorption and conversion platforms.

Synthesis of HER-capable cobalt metal organic framework using a straightforward reflux method and a thorough spectroscopic and theoretical analysis

A Cobalt MOF was obtained under reflux using aqueous methanol. The Cobalt MOF was synthesized using Cobalt (II) perchlorate hexahydrate and 1,3,5-Benzenetricarboxylic Acid (BTC) in a methanol mixed with double distilled water as a solvent under reflux condition for 2–3 h at 60–65 °C. The reddish solution obtained was filtered and kept in the refrigerator for almost 24 h. A crystal suitable for SC-XRD was obtained and the XRD analysis confirmed the polymeric structure of the Co-BTC. All the other analysis such as FTIR, Thermal analysis and FESEM of Co-BTC was carried out. Further, the efficacy of it as a potential catalyst towards HER was explored. The theoretical study assisted, and the data suggests that low band gap of the MOF possibly favors its efficacy in the Hydrogen Evolution Reaction (HER).

The role of Ga and Y on binary Al2O3-Y2O3 and Al2O3-Ga2O3 mixed oxides nanoparticles towards potential Ni water-gas shift catalysts

This work focuses on the study of binary Al2O3-Y2O3-x and Al2O3-Ga2O3-x mixed oxides with varying Y2O3 or Ga2O3 nominal loading (x=25, 50) prepared by hydrothermal synthesis assisted by Triton X-100. The mixed oxides were used to prepare Ni-based (5 wt%) catalysts for the Water Gas Shift Reaction. The Al2O3 sample presented urchin-like hollow nanosphere morphology, which evolved to solid nanospheres with Y2O3 or Ga2O3 in the mixed oxides. The physicochemical characterization indicated good integration of the mixed oxides, especially on the low-content additive oxides. The theoretical results confirmed that Ga goes deeper into the alumina matrix than Y, partially explaining the XPS and HRTEM results in which the Ni dispersion was better in the Ni/AlGa-x samples. The FTIR in-situ measurements of the reaction allowed us to propose that the reaction occurs minimally through the carbonyl mechanism at low temperatures (<300 °C) and the formate mechanism at high temperatures (>300 °C).