High-performance Catalysts Research Articles

Hydrothermal Valorization of Biosugars with Heterogeneous Catalysts: Advances, Catalyst Deactivation, Mitigation Strategies and Perspectives.

Sustainable production of valuable biochemicals and biofuels from lignocellulosic biomass necessitates the development of durable and high-performance catalysts. To assist the next-stage catalyst design for hydrothermal treatment of biosugars, this paper provides a critical review of (1) recent advances in biosugar hydrothermal valorization using heterogeneous catalysts, (2) the deactivation process of catalysts based on recycling tests of representative biosugar hydrothermal treatments, (3) state-of-the-art understandings of the deactivation mechanisms of heterogeneous catalysts, and (4) strategies for preparing durable catalysts and the regeneration of deactivated catalysts. Based on the review, challenges and perspectives are proposed. Some remarkable achievements in heterogeneous catalysis of biosugars are highlighted. The understanding of catalyst durability needs to be further enhanced based on full examination of the catalytic performance based on the conversion of substrates, the yield, and selectivity of products. Further, a full examination of the physiochemical changes based on multiple characterization techniques is required to eclucidate the relationships between treatment variables and catalyst durability. Collectively, a clear understanding of the relationships between chemical reaction pathways, treatment variables, and the physiochemistry of catalysts is encouraged to be gained to advise the development of heterogeneous catalysts for long-term and efficient hydrothermal upgrading of biosugars.

Facile Synthesis of Metal/Carbide Hybrid toward Overall Water Splitting

The development of cost-effective and high-performance bifunctional catalysts for overall water splitting is crucial for achieving sustainable clean energy. In this study, a metal/carbide hybrid (NiFeMo/NiFeMoCx) was prepared through fast and facile cathodic plasma electrolytic deposition. Due to the synergistic effect between the metal and carbide, NiFeMo/NiFeMoCx exhibited high activity in both the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER), with overpotentials of 230 mV and 60 mV at 10 mA cm−2, respectively. In addition, robust stability was demonstrated during the overall water splitting (1.52 V at 10 mA cm−2, with little degradation after 18 h of catalysis). This work provides a useful strategy for designing advanced water splitting catalysts for real application.

Structural design and electronic regulation of atomically dispersed Mo-S4 sites by second shell N species reconfiguration for intensifying hydrogen spillover

Intensifying hydrogen spillover by regulating the atomic local structures catalysts is crucial for improving the hydrogenation performance, but still hugely challenging. Herein, we report a robust single-atom catalyst featuring Mo-S4 sites in the first shell modulated with N atoms in the second shell (Mo-S4-N/C) by an efficient cyclodextrin supramolecular self-assembly pyrolysis strategy for intensifying hydrogen spillover in slurry-phase hydrocracking of vacuum residue (VR). We discovered that the H2 is activated at the single-atom Mo-S4 sites efficiently and the spillover of active hydrogen is accelerated by the reconfiguration of N species in the second shell. Remarkably, the Mo-S4-N/C catalyst demonstrates excellent catalytic hydrogenation activity with high turnover frequency calculated for total metals up to 0.46 s−1, the VR per pass conversion of 61 wt.%, liquid product yield of 94 wt.%, and the low coke content of 0.6 wt.%, along with good stability, respectively. Theoretical calculations revealed that the N species in the second shell regulated the electronic structure of Mo-S4 sites, promoting the migration of active hydrogen species by reducing the transfer energy barrier of hydrogen spillover, thus enhancing the hydrogenation performance. This work proposed a strengthened hydrogen spillover mechanism from the atomic scale for hydrogenation reaction, offering novel concepts for designing and developing high-performance hydrogenation catalysts.

In Situ Growth of MoN on Nickel Foam for Highly Efficient Hydrogen Evolution in Alkaline Solution.

Highly efficient, stable, and low-cost hydrogen evolution catalysts are urgently required for water electrolysis. Herein, a method for in situ growth of medium-nitrogen nanosheet MoN catalysts with a large electrochemical surface area on nickel foam (NF) is proposed. The results show that the morphology of the as-prepared catalysts greatly depends on the nitrogen sources and nitridation temperature. The MoN/NF catalyst nitride at 700 °C using melamine as a nitrogen source exhibits a spindle-like morphology consisting of stacked nanosheets, which is conducive to exposing more active sites, thereby increasing the catalyst activity. The N atoms in MoN could adjust the chemical environment of the metal by changing the density of the d-band electron state, which further improves the HER performance. Benefiting from the regulation of Mo charge distribution and exposure to more active sites through N doping and morphological control, the MoN/NF catalyst exhibits superior HER performance with an overpotential of 70 mV at a current density of 10 mA·cm-2, a Tafel slope of 44.3 mV dec-1, and an Rct of 1.83 Ω, indicating high HER catalytic activity, fast kinetics, and excellent conductivity. Theoretical calculations reveal that among the (002), (202), and (200) planes of MoN, the (202) plane exhibits the lowest value of |ΔGH*| (0.47 eV), which is close to that of Pt(111) (0.14 eV). More importantly, MoN(202) also has the smallest work function of 3.58 eV, indicating an enhanced capability to offer electrons. This work develops a strategy to design high-performance and low-cost transition-metal nitride HER catalysts.

Redox-mediated decoupled seawater direct splitting for H2 production

Seawater direct electrolysis (SDE) using renewable energy provides a sustainable pathway to harness abundant oceanic hydrogen resources. However, the side-reaction of the chlorine electro-oxidation reaction (ClOR) severely decreased direct electrolysis efficiency of seawater and gradually corrodes the anode. In this study, a redox-mediated strategy is introduced to suppress the ClOR, and a decoupled seawater direct electrolysis (DSDE) system incorporating a separate O2 evolution reactor is established. Ferricyanide/ferrocyanide ([Fe(CN)6]3−/4−) serves as an electron-mediator between the cell and the reactor, thereby enabling a more dynamically favorable half-reaction to supplant the traditional oxygen evolution reaction (OER). This alteration involves a straightforward, single-electron-transfer anodic reaction without gas precipitation and effectively eliminates the generation of chlorine-containing byproducts. By operating at low voltages (~1.37 V at 10 mA cm−2 and ~1.57 V at 100 mA cm−2) and maintaining stability even in a Cl−-saturated seawater electrolyte, this system has the potential of undergoing decoupled seawater electrolysis with zero chlorine emissions. Further improvements in the high-performance redox-mediators and catalysts can provide enhanced cost-effectiveness and sustainability of the DSDE system.

Highly enhanced electrocatalytic OER with facile electrodeposition of MIL–53(Fe)/NiAl–LDH/NF and NiAl–LDH/MIL–53(Fe)/NF

This research investigates a new approach to improve the electrocatalytic rate of the Oxygen Evolution Reaction (OER), a key step in water electrolysis. The study focuses on two promising materials: MIL–53(Fe) and NiAl–LDH. MIL–53(Fe) offers several advantages: high catalytic activity, large surface area, and good chemical stability. NiAl–LDH is attractive due to its layered structure, tolerance to a wide range of pH levels, scalability, and cost-effectiveness. However, their limitations like low conductivity and restricted accessibility of active sites hinder their performance in water splitting applications. To address these limitations, novel composite thin films were created using a technique called layer–by–layer (LBL) electrophoretic deposition. These films, built on nickel foam (NF) substrates, included two configurations: MIL–53(Fe)/NiAl–LDH/NF and NiAl–LDH/MIL–53(Fe)/NF. The MIL-53(Fe)/NiAl-LDH/NF composite exhibited remarkable OER activity in alkaline electrolytes, requiring overpotentials of only 200, 270, and 370 mV to reach current densities of 20, 50, and 100 mA cm−2, respectively. The Tafel slope of 54.86 mVdec−1 suggests rapid reaction kinetics. Additionally, it demonstrated excellent long-term stability, lasting for at least 20 h. The success of the MIL–53(Fe)/NiAl–LDH/NF composite can be attributed to the LBL technique. This method creates a composite with a larger surface area, significantly improving OER efficiency. In contrast, the MIL–53(Fe)/NiAl–LDH/NF configuration had the opposite effect. The NF pores became blocked by the MIL–53(Fe) layer, reducing the overall surface area, hindering electron transfer, and thereby limiting oxygen production. The LBL deposition method used in this study proves its effectiveness in designing efficient electrocatalysts. This opens up possibilities for creating other multicomponent materials for energy applications. The findings provide valuable insights for future research on these promising composite materials, potentially leading to the development of cost-effective and high-performance catalysts for various electrochemical applications.

Recyclable polyethylenimine based polymer for selective Pd(II) recovery and Suzuki reaction: Waste to treasure tactics

Developing efficient materials for the selective capture of Pd(II) from secondary sources, along with the reutilization of spent Pd(II)-loaded adsorbents, is of great significance, but remains great challenging. Herein, a highly efficient adsorbent (TP@PEI) was fabricated through polycondensation of polyethyleneimine (PEI) with 1,3,5-triformylphoroglucinol (TP), which selectively extracts palladium ions from simulated industrial wastewater, with preferential uptake of Pd(II) over 9 competing cations. The TP@PEI achieves ultrafast capture of Pd(II) in just 20 min, with an impressive adsorption capacity of 620 mg g−1. Of greater significance, the removal efficiency for Pd(II) reaches 99.9 % at a concentration of 100 mg L-1, which still remains at a remarkable 99 % after 11 adsorption–desorption cycles. Exceptional 99.9 % Pd(II) recovery is achieved through the adsorption of a depleted Pd-digested solution, while the breakthrough test validates its practicality and impressive bed breakthrough time (1070 min). Mechanism study reveals that the exceptional adsorption performance of TP@PEI for palladium is driven by synergistic interactions, including coordination and electrostatic interactions. Furthermore, the waste Pd(II) loaded TP@PEI efficiently catalyzes the Suzuki reaction in water, achieving a remarkable 99 % yield of the targeted compound. This research showcases a strategy for converting industrial waste into a valuable resource by meticulously engineering materials to extract precious metals from wastewater, subsequently repurposing them as high-performing catalysts.

Synergistic Coordination Effect and Metal-Support Interaction Engineering of Single-Atom Mn-N2 Sites for Boosting Sensitive and Selective Dopamine Biosensing in Human Serum.

Coordination environment of metal atoms is core for designing high-performance single-atom catalysts (SACs), while metal-support interaction also has an important effect on structure-function relationship. Nevertheless, the interaction effect of metal-support is mostly ignored. Through synergistic regulation of coordination environment and metal-support interaction, Mn SAC with atom-dispersed Mn-N2 sites on dopamine (DA) support is synthesized for sensitive and selective DA oxidation based on theoretical calculations and experimental explorations. MnN2 presents the more optimal catalytic site for DA oxidation than other coordination conditions, enhancing sensitivity including a wide range, a low limit of detection, and particularly a very low catalytic potential. The construction of Mn-N2 active sites on DA carbon promotes the coupling between Mn metal atoms and DA support, decreasing work function, facilitating electron exchange, shortening response time, and boosting selectivity. Both the catalytic mechanism of Mn SAC toward DA and the relation construction of catalyst's structure and catalytic function are established.

Construction of Co-CN as a high-performance catalyst for photocatalytic tetracycline degradation and mechanism study

Constructing highly efficient and stable catalysts for tetracycline degradation is very important in avoiding harm to human and ecosystem health. Herein, we doped Co-MOF into carbon nitride (CN) and synthesized successfully a copolymer Co-CN with heterojunctions structure simple intramolecular doping. Various characterization results demonstrate that Co2+ cations are highly dispersed on the CN support. The Co-CN catalyst exhibited outstanding degradation efficiency and recycle stability for tetracycline (TC) degradation, demonstrates a degradation efficiency of 85.2% under benign conditions. Various characterization results revealed the pathway and mechanism of TC degradation. An intramolecular heterojunction structures in Co-CN copolymers promote charge separation and transport efficiency, which make a variety of active species to be generated in the reaction system. Free radical trapping experiment results show that four active species including h+, 1O2, ·O2− and ·OH synergistically catalyze to activate the substrate to achieve degradation of TC molecules.

Electrocatalytic nitrite conversion to ammonia over Mn single atoms anchored on MoO3-x

Electrocatalytic reduction of NO2 to NH3 (NO2RR) offers a promising route to attain harmful NO2– removal and valuable NH3 production. Herein, Mn single atoms anchored on oxygen vacancy-rich MoO3-x (Mn1/MoO3-x) are developed as a high-performance catalyst for the NO2RR. Atom characterizations unravel that the isolated Mn atoms exist as Mn1-O5 moieties on MoO3-x. Theoretical calculations and in situ electrochemical spectroscopic measurements unveil that Mn1/MoO3-x follows a Langmuir-Hinshelwood mechanism to drive the NO2RR process, in which Mn1-O5 site facilitates the adsorption and activation of NO2– to form the intermediates, while MoO3-x substrate dissociates H2O to yield *H. The generated *H is then transferred from MoO3-x substrate to Mn1-O5 site which promotes the intermediate protonation to produce NH3. Remarkably, Mn1/MoO3-x in flow cell reaches the high NH3 yield rate of 546.25 μmol h−1 cm−2 and NH3-Faraday efficiency of 92.6 %, outperforming most reported NO2RR catalysts.

Atomically dispersed iron sites from eco-friendly microbial mycelium as highly efficient hydrogenation catalyst

Iron, one of the most abundant elements on earth and an essential element for living organisms, plays a crucial role in our daily metabolism. In the field of catalysis, the development of high-performance catalysts based on less toxic iron element is also of significant importance for green chemistry and a sustainable future. To construct Fe-based heterogeneous catalysts with excellent hydrogenation performance, precise modulation of the atomic coordination structure is a key strategy for enhancing catalytic activity. In this study, we present an in-situ coating method for applying a zeolitic imidazolate framework (ZIF) onto the surface of fungal hyphae. The asymmetric coordination structure of Fe1-N3P1 was precisely tailored by utilizing the phosphorus source from the fungus and the nitrogen source in the ZIFs. Detailed characterizations and density functional theory calculations revealed that the incorporation of ZIFs not only increased the specific surface area of catalysts, but also facilitated the dispersion of Fe2P nanoparticles into the Fe1-N3P1 center, making the lowest reaction energy barrier and resulting in the best performance for nitrobenzene hydrogenation when compared to the Fe2P nanoparticles and clusters. This research introduces a novel design concept for constructing asymmetric monoatomic configuration based on the inherent characteristics of natural microorganisms and the exogenous porous coordination polymers.

Facilitating CO2 methanation over oxygen vacancy-rich Ni/CeO2: Insights into the synergistic effect between oxygen vacancy and metal-support interaction

The catalytic hydrogenation of CO2 into CH4 is a versatile strategy to realize green development goals, whereas developing low-cost and high-performance catalysts remains a significant challenge. Herein, highly active Ni0/NiO supported on oxygen vacancy-rich CeO2 (Ni/CeO2-Ov-R) was designed, which exhibited ∼76 % CO2 conversion coupled with 100 % CH4 selectivity at a low temperature of 250 °C. In addition, such satisfactory reaction performance could be maintained over 80 h at 300 °C. The density functional theory (DFT) calculations elaborated that oxygen vacancies were more easily formed on the CeO2 (1 1 0) plane of Ni/CeO2-Ov-R. Compared with Ni/CeO2-Ov-medium (Ni/CeO2-Ov-M) and Ni/CeO2-Ov-poor (Ni/CeO2-Ov-P) with relatively insufficient oxygen vacancy, the copious oxygen vacancies of Ni/CeO2-Ov-rich was apt to enhance the interaction between the CeO2 support and Ni species as confirmed through H2-TPR and XPS. Noteworthily, the abundant medium-strength basic sites and surface oxygen vacancy of Ni/CeO2-Ov-rich were more conducive to upshifting the activation adsorption of CO2 and accelerate the conversion of intermediates. Besides, the oxygen vacancies also make a great contribution to the enhancement of the potential for hydrogen dissociation because of the enhanced number of exposed Ni0. In situ DRIFTS displayed that the CO and formate (HCOO–) routes co-existed on Ni/CeO2 catalysts, revealing that oxygen vacancy and exposed Ni0 boosted the CO2 and H2 activation. This work proposes a deeper insight into the precise regulation of the oxygen vacancy of Ni/CeO2 catalyst and opens a path for exploiting CO2 methanation catalysts with a potential application.

Oxidation of Toluene over the Pt-Embedded Mesoporous CeO2 Hollow Nanospheres with Advanced Catalytic Performances.

In this study, the novel Pt-embedded mesoporous CeO2 hollow nanospheres (Pt-MS-CeO2-H) with varying Pt contents (0.5-3.0 wt %) were facilely prepared. The Pt nanoparticles were one-pot embedded within the mesoporous shell of Pt-MS-CeO2-H and assisted with the reduction Ostwald ripening process. The traditional preparation methods often face challenges, such as the uneven distribution or aggregation of nanoparticles, as well as difficulty in maintaining high catalytic activity at low Pt content. Compared with the traditional supported Pt/MS-CeO2 catalyst, the embedding strategy facilitated precise control over the position, distribution, and uniformity of Pt nanoparticles within the CeO2 mesoporous shell. Additionally, the encapsulation process of Pt nanoparticles played a pivotal role in generating oxygen vacancies and activating surface chemical adsorption of oxygen. Resultantly, the toluene oxidation performances of 1Pt-MS-CeO2-H catalyst showed much lower T90 (171 °C) than 1Pt/MS-CeO2 (311 °C). To elucidate the underlying reasons, in situ diffuse reflectance infrared Fourier transform spectroscopy of toluene oxidation was employed to identify the reaction intermediates and pathways over these catalysts. In summary, the Pt-embedded mesoporous CeO2 hollow nanosphere catalysts were considered as potential candidates when designing high-performance toluene catalytic oxidation catalysts.

Fine regulation of self-supporting metal phosphonates for improved overall water splitting

The exploration of high-performance water electrolysis catalysts is crucial for the development of hydrogen energy and the alleviation of increasingly serious environmental problems. Transition metal phosphonates are very promising electrocatalysts. In this work, a new nickel phosphonate has been synthesized and successfully developed into high-performance electrocatalyst through in-situ growth on nickel foam (NF), introduction of iron, and adjustment of Ni:Fe mole ratio. It is revealed that NiFe12 and NIFe13 exhibit the best OER (η10: 268 mV vs. RHE; Tafel slope: 54 mV dec−1) and HER (η10: 172 mV vs. RHE; Tafel slope: 77 mV dec−1) catalytic activity under optimized conditions, respectively, with fast reaction kinetics and long-term durability. The water electrolysis device assembled with them can drive a current density of 10 mA cm−2 at low voltage (1.68 V) with long-term durability, demonstrating promising application prospects. This work has important reference significance for the development of transition metal-based water electrolysis catalysts.

Liquid Nitrogen Exfoliation and Nanodispersion of WS2 for Thermocatalysts.

The efficient and clean exfoliation of single and/or few-layer nanosheets of WS2, a two-dimensional transition metal dichalcogenides, remains a significant challenge. In this study, a simple exfoliation method was proposed to produce ultrathin WS2 nanosheets by combining the liquid nitrogen exfoliation and nanodispersion techniques. This approach efficiently exfoliated WS2 into several layers of nanosheets via rapid temperature changes and mechanical stress without inducing defects or contamination. After five cycles of heating/liquid nitrogen and nanodispersion, the resulting WS2 nanosheets (WS2-5N ND) were confirmed to have been successfully exfoliated into 1-4 layers. When applied as a promoter in a thermocatalyst for the selective catalytic reduction of NOX using NH3, 2V3WS2/Ti (WS2-5N ND) exhibited excellent NOX conversion and N2 selectivity, along with excellent durability even in the presence of SO2. This result was greater than 2V3WS2/Ti (WS2-5N) subjected to only liquid nitrogen exfoliation, proving the importance of the simultaneous action of both methods. This method is expected to be an important contribution to ongoing research on high-performance WS2-based catalysts, thereby opening up potential opportunities for a wide range of applications.

Important structural parameter for curvature effect of TM-N4 embeded C70 fullerenes as electrocatalysts for CO2 reduction interpreted with machine learning and first-principles calculations

In this work, TM-N4 sites embedded on curved C70 Fullerenes (TMN4(n)@C64, n = 1–5 which denote the doping positions and TM = Sc-Zn) were designed as efficient catalysts for electrochemical CO2 reduction reaction (ECO2RR). With interpretable machine learning (ML) and first-principles calculations, the performance of TM-N4 sites as possible electrocatalysts for ECO2RR under the curvature effect were revealed. After the screen procedure of catalyst stability, CO2 activation and selectivity of 50 designed systems, VN4(3), CrN4(3), MnN4(2), FeN4(2, 3, 5)@C64 were identified as high performance catalysts for ECO2RR to CH4, with limiting potential of -0.41 V, -0.26 V, -0.28 V, -0.35 V, -0.25 V and -0.17 V respectively, outperform the TM-N4 catalysts on the flat surface. A key structural descriptor K which can reflect the curvature effect of TM-N4 sites on the curved surface was identified with ML models. The gradient boosting regression (GBR) and sure independence screening and sparsifying operator (SISSO) algorithm reveal that the structural parameter K have strong association with the CO2 adsorption and significant influence on the selectivity of catalysts. Interestingly, the structural parameter K can influence more the binding of O-bonded intermediates than C-bonded intermediates. With the GBR algorithm, an effective model for the prediction of the limiting potential for C1 products were obtained. This study clarified the curvature effect of TM-N4 supported on the curved surface, and provides valuable guidance for the designing of TM-N4 single atom catalysts for ECO2RR on curved surface.

Co–Ni bimetallic oxide with tuned surface oxygen vacancies efficiently electrocatalytic reduction of nitrate to ammonia

The electrocatalytic reduction reaction of nitrate (NO3−) to ammonia (NH3) provides an efficient and clean NH3 production method, which has the potential to replace the traditional industrial preparation methods. However, the limited activity and Faraday efficiency (FE) of existing catalysts impede the practical application of this technology. Herein, in this work, a high-performance catalyst with high NH3 yield and FE was fabricated. Co–Ni bimetallic oxide (NiCo2O4) catalysts with tuned surface oxygen vacancies (OVs) contents were prepared by changing the heating rate during calcination, NiCo2O4 calcined at a heating rate of 5 °C/min (NiCo2O4-5) possessed the highest surface OVs content. Experimental studies showed that NiCo2O4 with higher surface OVs had better NO3RR activity, inhibited the production of nitrite (NO2−), and exhibited higher selectivity to NH3. Among prepared catalysts, NiCo2O4-5 demonstrated superior performance in electrocatalytic reduction of NO3− to NH3, achieving a high NH3 FE (94.4 %) and yield (193.2 mmol/h g−1) at a suitable applied voltage. Besides, in situ Fourier transform infrared spectroscopy analysis suggested that NiCo2O4-5 preferentially followed the NO3RR pathway as follows: *NO3 → *HNO3 → *NO2 → *HNO2 → *NO → *HNO → *N → *NH → *NH2 → *NH3.

Synergistic effects of feni bimetal-doped biochar on oxygen evolution reaction kinetics: A one-step, low-temperature pyrolysis approach

As the hydrogen energy sector progresses, water electrolysis technology played a crucial role in producing green hydrogen. A major challenge in this endeavor lied in the oxygen evolution reaction (OER), where the overpotential has consistently been high leading to an increase in the energy demand. This study developed a one-step pyrolysis technique to transform metal-supported biomass into FeNi/NC catalysts having enhanced crystallinity and defect sites. This process without activation step using strong acids or bases reduced the operational procedures and the treatment of intermediate products, which reduced the technical difficulty. As the pyrolysis temperature increases, the metal ions in the biochar gradually formed stable metal oxides, which catalyze the alkaline OER and markedly boosted catalytic efficiency. Crucially, the abundance of lattice oxygen and oxygen vacancies in the catalyst played a key role in enhancing the OER kinetics. Notably, the catalyst pyrolyzed at 750 °C demonstrated good performance, with an overpotential of 270 mV at a concentration of 10 mA cm−2 of the density of current, which was superior to RuO2(η10=315 mV) and IrO2(η10=300 mV). Overall, this study reported an approach for the fabrication of high-performance OER catalysts and the strategic utilization of biomass resources for application in clean energy technologies.

Ultrafine Pd nanoparticles confined in naphthalene-based covalent triazine frameworks for efficient and stable hydrogen production from formic acid

Formic acid (FA) is considered as a kind of promising hydrogen storage materials due to its economic feasibility, safety, stability and high hydrogen density. Nevertheless, it is a challenge to design a high-performance catalyst with high activity, selectivity and stability for the dehydrogenation of FA to generate hydrogen (H2). Herein, a range of covalent triazine frameworks (CTFs including 1,8-CTF, 1,5-CTF and 2,3-CTF) with abundant nitrogen atoms are developed to support palladium nanoparticles for efficiently catalyzing FA dehydrogenation. Ultrasmall palladium nanoparticles with a size of 1.2 ± 0.3 nm showed near 100 % H2 selectivity and high catalytic activity in FA dehydrogenation supported by 1,8-CTF. The activation energy of FA dehydrogenation catalyzed by Pd/1,8-CTF reaches 26.17 kJ·mol−1. In addition, Pd/1,8-CTF exhibits high stability and easy recyclability, and the catalytic activity is maintained even after 6 cycles. This work gives a feasible strategy to develop high-efficiency and selective nanocatalysts for H2 production from FA dehydrogenation.

Integrating Active Learning and DFT for Fast-Tracking Single-Atom Alloy Catalysts in CO2-to-Fuel Conversion.

Electrocatalytic carbon dioxide reduction (CO2RR) technology enables the conversion of excessive CO2 into high-value fuels and chemicals, thereby mitigating atmospheric CO2 concentrations and addressing energy scarcity. Single-atom alloys (SAAs) possess the potential to enhance the CO2RR performance by full utilization of atoms and breaking linear scaling relationships. However, quickly screening high-performance metal portfolios of SAAs remains a formidable challenge. In this study, we proposed an active learning (AL) framework to screen high-performance catalysts for CO2RR to yield fuels such as CH4 and CH3OH. After four rounds of AL iterations, the ML model attained optimal prediction performance with the test set R2 of approximately 0.94 and successful prediction was achieved for the binding free energy of *CHO, *COH, *CO, and *H on 380 catalyst surfaces with an accuracy within 0.20 eV. Subsequent analysis of the SAA catalysts' activity, selectivity, and stability led to the discovery of eight previously unexplored SAA catalysts for CO2RR. Notably, the surface activity of Ti@Cu(100), Au@Pt(100), and Ag@Pt(100) shines prominently. Utilizing DFT calculations, we elucidated the complete reaction pathway of the CO2RR on the surfaces of these catalysts, confirming their high catalytic activity with limiting potentials of -0.11, -0.34, and -0.46 eV, respectively, which are significantly lower than those of pure Cu catalysts. The results showcase the exceptional predictive prowess of AL, providing a valuable reference for the design of CO2RR catalysts.