ChemCatChem最新文献

The potential of saponite clays, hydrous magnesium silicates with low content of aluminium, is investigated in the selective isopropanol catalytic dehydration to propylene. Their performances are compared with the activity of montmorillonite clays, low-alumina zeolite and amorphous silica–aluminas. All solids were characterized by XRD, N₂ sorption isotherms, TGA-IR, NH₃ adsorption FTIR, NH₃/SO₂ adsorption microcalorimetry, and solid-state ¹H and ²⁷Al NMR. The physico-chemical analyses show that the samples are predominantly mesoporous, except zeolite, with BET surface areas ranging from 130 to 430 m²/g. All catalysts display acidic character and are thermally stable below 300°C. Their catalytic performances were evaluated by using a pulse catalytic reactor set inside a calorimeter (DSC-GC). This technique offers a convenient way to screen industrially relevant temperature regimes that balance activity, selectivity and process economy of different type of solids. Catalytic testing revealed that below 150°C, clays outperformed amorphous silica-aluminas, whereas the zeolite, although giving high conversion, is not suitable for the application due to a low selectivity to propylene (10%). An optimized activation temperature is the key parameter allowing clays to preserve structural stability, moderate surface area with favorable pore structure and to maintain a suitable number of acid sites.

Heterogeneous photocatalysis has progressively evolved to address solar-to-chemical energy conversion bottlenecks. Although earlier generations established foundational principles, they faced limitations in atomic efficiency and charge transfer. This review critically analyzes fourth generation photocatalysts, a paradigm defined by atomic precision and dynamic interface engineering on TiO₂ platforms. Distinct from classical models, this generation leverages electronic/covalent metal–support interactions, where single-atom catalysts chemically integrate into the lattice via direct orbital bonding (e.g., Ti-O-M) to bypass recombination traps. We examine key charge separation breakthroughs, including self-healing redox cycles in Cu single atoms (56% quantum efficiency), exciton-mediated transfer in Mo-doped systems, and synergistic dual-junction architectures. Furthermore, the pivotal role of defect engineering (Ti³⁺, oxygen vacancies) in stabilizing atomic sites and tuning selectivity is highlighted. This review offers a unified framework for designing next-generation photocatalysts that overcome intrinsic bulk semiconductor limitations through atomic-level innovations.

Herein, we designed novel metal-organic frameworks (MOFs) with different metal and organic linkers to investigate the influence of the type and number of the metal cations and organic linkers on their electrocatalytic performances for the hydrogen evolution reactions (HER). For this purpose, MOF structures bearing mono and dual Co, Fe, and Ni metal and benzene tricarboxylic acid (BTC) and benzimidazole (BIM) linkers were easily synthesized using a solvothermal technique. Pristine MOF modified carbon cloth (CC) electrodes were finally tested as the cathode of the water electrolyzer to enhance the HER performances. The characterizations of the MOFs indicated that the MOFs bearing Co and Fe cations were coordinated with two organic linkers and two water molecules, which facilitated their electrocatalytic activity by opening ways to the active sites of the structure. The electrocatalytic results indicated that the Co²⁺ cation was found at the most active metal center, and BTC acted as the better ligand option. Among the modified electrodes, CC/Co-BTC exhibited superior HER performances with 7.00 cm² of ECSA, 43 mV of overpotential, 80 mVdec⁻¹ of Tafel slope, and excellent coulombic stability. These results indicate the possible usage of the CC/Co-BTC electrode instead of the commercial CC/Pt electrode in practical water electrolysis processes.

This review systematically summarizes recent advances in photothermal catalysis for converting CO₂ into high-value C1 products (e.g., CO, CH₄, and CH₃OH). The review begins with the fundamental principles of photothermal synergy and explains how full-spectrum utilization helps overcome thermodynamic and kinetic bottlenecks. This review focuses on rational catalyst design, particularly the role of alloyed catalysts in regulating electronic structures and surface reaction pathways. It also highlights how biomimetic photothermal catalysts mimic natural photosynthesis to achieve efficient energy-to-matter conversion. The review further surveys diverse catalytic systems, from Local Surface Plasmon Resonance (LSPR) metals and semiconductors to MOF/COF composites, and summarizes performance optimization strategies based on surface and defect engineering. Unlike previous reviews, a dedicated section discusses mass and heat transfer challenges in reactor engineering and scale-up, extending the perspective from material microstructures to macroscopic system integration. Finally, the review synthesizes current challenges and identifies future directions in atomic-level catalyst design, photo-thermal coupling mechanisms, and process techno-economic evaluation. This review aims to provide theoretical insights and a technical roadmap for designing efficient, stable, and scalable photothermal catalytic systems, ultimately advancing practical solar fuel production.

High energy consumption during regeneration limits the industrial scalability of organic amine CO₂ capture. Catalytic desorption offers a solution by introducing solid acid catalysts to lower sensible, vaporization, and reaction heat, thereby enabling efficient regeneration and low-temperature, high-purity CO₂ release. This study reviews catalyst design strategies and performance, clarifying the underlying mechanisms of catalytic desorption. It concludes by discussing remaining challenges and future prospects, particularly the application of machine learning (ML) for the rational design of superior catalysts.

Ordered intermetallic bimetals have offered wide application for hydrogen (H₂) production from hydrogen evolution reaction (HER) electrocatalysis, but commercial implementation is still slow than expected due to insufficient activity and stability. In this work, by alloying Ni atoms into intermetallic PtCo bimetals and being further stabilized into mesoporous carbon skeleton (i-Pt₁Co_xNi_1-x@MC), the electrocatalyst disclosed remarkably high HER performance in a wide pH range. Mechanism studies revealed that alloying Ni in PtCo bimetals resulted in the electron-deficient state of Pt sites, which optimized the H₂O dissociation and facilitated H₂ coupling in Heyrovsky step for active and stable HER electrocatalysis. Compared to other counterpart electrocatalysts, trimetallic i-Pt₁Co_xNi_1-x@MC disclosed the best performance in 1.0 M KOH, with a mass activity of 3.76 A mg⁻¹ and a specific activity of 30.79 mA cm⁻² at an overpotential of 100 mV. Meanwhile, high HER stability was also achieved for 5000 cycles with well-retained structure and orderliness. The high performance of HER electrocatalysis in a wide pH range is expected to highlight practical application under harsh conditions.