Applied Catalysis B: Environmental最新文献

Ethanol synthesis through CO₂ hydrogenation has shown great promise in contributing to carbon neutrality. Herein, we for the first time present the phosphorus-substitution of atomically dispersed Rh-N₄ sites for the title reaction. The as-formed Rh-N₃P₁ sites enable the reaction product notably switching from nearly total methanol (91.3%) towards major ethanol (81.8%) with a high TOF of 420.7 h⁻¹. This outstanding promotion in both ethanol formation and CO₂ conversion (69% higher) could be assigned to the donation of electron from P atom effectively weakening C-O bond in CH₃OH* , facilitating its cleavage into CH₃ * , and enabling the coupling between CO* and CH₃ * . The presence of Rh-P site pair assists C-O bond activation with a longer bond length owing to a strong affinity of P atom to O atom in CH₃OH* . This research underscores the importance of tuning the coordination and electronic environment of active metal sites for site pair synergistic catalysis.

Highly dispersed and stable metal catalysts with small nanoparticles have received extensive attention in elevated-temperature thermocatalytic process. However, the available strategies to stabilize metal sites, by constructing defective structures on catalyst supports and developing controllable preparation steps at room temperature, show limited effect, because these active metal sites can be mobile and sintering at elevated temperature. Herein, dealuminated Beta zeolite with abundant surface defects of silanol nests is applied as support, then dynamic trap strategy and subsequent reduction process at elevated temperature is devoted to transfer Ni-based precursors into the silanol nests, thus obtaining small nanoparticles Ni catalysts that are suitable for high-temperature methane dry reforming (DRM). Some in-situ characterization processes and the ingenious designed experiments are performed to identify the dynamic trapping process. The rational fabricated catalysts exhibit high catalytic reactivity for DRM reaction in long-term operation.

The efficiency and sustainability for the recycling of plastic wastes into hydrogen was investigated. An integrated microwave-driven valorization of plastic wastes and CO₂ for H₂ and CO production was proposed. Specifically, plastic wastes were decomposed into H₂ and solid carbons, followed by carbon elimination via CO₂ gasification under microwave irradiation. Through the high-throughput screen of catalysts as well as the optimization of key parameters, over 96% hydrogen was converted into H₂ with a yield of 480 mmol∙g⁻¹H_plastic while the carbon conversion and CO₂ conversion reached up to 70% and 53%. The five-cycle successive test displayed extraordinarily high and stable catalytic activity due to the facile elimination of carbon deposition. The application for real-world plastic wastes further demonstrated the efficient microwave-driven CO₂ gasification of plastic wastes into H₂ and CO production as a feasible and sustainable technology toward the waste-to-energy circular economy.

Carbon-supported ruthenium catalysts facilitate electrically-assisted Haber–Bosch ammonia synthesis. However, the relationship between carbon supports and catalytic performance remains ambiguous. We developed ordered mesoporous carbon plates (MCPs) with varying graphitization degrees as Cs-promoted Ru catalyst supports, examining correlations between ammonia synthesis rate and key structural parameters, included graphitization degree, Ru nanoparticle size, and Cs/Ru ratio. High-graphitization-degree carbon supports resisted methanation and facilitated formation of reductive activation enabled dynamic Cs⁰ species as electronic promotor, induced by spillover hydrogen from the Ru surface to CsOH. Density functional theory calculations further revealed that CsOH alleviated hydrogen poisoning. Notably, the catalyst supported on MCP-1100—which exhibited the highest graphitization degree among the supports and superior stability—with 10 wt% 2.3-nm-sized Ru nanoparticles and Cs/Ru = 2.5 achieved high ambient-pressure ammonia synthesis rates (7.9–43 mmol_NH3·g⁻¹·h⁻¹) below 410 °C. Furthermore, it functioned under intermittent operating conditions, potentially integrating renewable-electricity-based electrolytic hydrogen production.

In this paper, the Ru/RuS₂ nanoparticles as dual co-catalysts were self-assembled on the surface of g-C₃N₄ nanotubes (Ru/RuS₂/g-C₃N₄ NTs) for photocatalytic H₂ production. The Ru/RuS₂/g-C₃N₄ NTs showed greatly enhanced photocatalytic H₂ production activity (1409 μmol·g⁻¹·h⁻¹), 1.16 times of RuS₂/g-C₃N₄ NTs (1212 μmol·h⁻¹·g⁻¹), 10.51 times of Ru/g-C₃N₄ NTs (134 μmol·g⁻¹·h⁻¹), and 82.88 times of the pure g-C₃N₄ NTs (17 μmol·g⁻¹·h⁻¹). Besides, the apparent quantum yield value (AQE) of Ru/RuS₂/g-C₃N₄ NTs is 3.92% at 370 nm. Ru/RuS₂ as dual co-catalysts are self-assembled on the surface of g-C₃N₄ NTs and show strong electronic synergistic interaction between the interfaces, reduce ΔG_H* of RuS₂ and desorption energy of Ru, and promote the selectivity and activity of HER kinetically and thermodynamically respectively, which exhibits higher photogenerated carrier concentration and lower charge migration resistance than RuS₂ and Ru, showing the synergistic effect to facilitate the generation and migration of carriers and provides active sites for photocatalysis.

Photocatalytic H₂O₂ production has gained significant attention as an environmentally friendly approach. The key is to explore efficient photocatalysts with sufficient active sites and excellent electron transfer capacity. Herein, we propose a novel approach by incorporating carbon dots (CDs) on ethylenediamine capped Zn_0.5Cd_0.5S, which was bridged with an interfacial amide bond. Smooth transfer of photoinduced electrons from Zn_0.5Cd_0.5S to carbon dots via a high-speed electron channel is afforded by interfacial amide bond. A remarkable H₂O₂ yield with a rate of 252 μmol/h and an apparent quantum yield (AQY) of 31 % at 400 nm is achieved. Photoelectrochemical analysis and density function theory (DFT) calculation reveal CDs with abundant oxygenous functional groups as active sites, boosting activity and selectivity. This interfacial engineering strategy with the acceleration of electrons transfer and enhanced 2e^- selectivity can be applied to advanced photocatalytic systems for the achievement of valuable organics, environmental purification and new energy carriers.

Selective catalytic conversion of biomass-derived compounds to fuels and fine chemicals serves as a renewable energy pathway for the partial substitution of fossil resources, in which reaction pathway and selectivity control are key issues. Herein, we report a fully exposed Pt clusters immobilized on CoAl mixed metal oxides catalyst (denoted as Pt_n/CoAl-MMOs), which exhibits prominent catalytic performance towards liquid phase hydrogenation reaction of furfural (FAL). Noteworthily, the hydrogenation chemoselectivity can be switched among four products via using four different solvents: tetrahydrofurfuryl alcohol (THFA; yield: 91.4%), furfuryl alcohol (FA; yield: 97.7%), 2-methylfuran (2-MF; yield: 92.1%) and furan (FU; yield: 90.8%) are obtained in ethanol, dioxane, isopropanol and n-hexane solvent, respectively. Experimental studies (in situ FT-IR and TPSR-Mass) combined with theoretical calculations (DFT) reveal that solvent molecules exert an essential influence on the adsorption configuration of FAL via changing the solvent-catalyst and/or substrate-catalyst interaction, which ultimately determines the hydrogenation pathway, key intermediate and final product. This work demonstrates a facile solvent-dependent product-switching strategy within one catalytic system, which opens up potential opportunities for tailoring hydrogenation selectivity in liquid-solid catalytic reactions towards biomass upgrading.

Metal M₁/metal oxide M₂O_x (M₁M₂O_x) inverse catalysts, where the oxide layer rests atop metal, have gained attention for their distinct catalytic performance. They are intensively studied in biomass upgrading, e.g., the hydrogenolysis of tetrahydrofurfuryl alcohol to produce 1,5-pentanediol. Pt and MO_x (M = W, Mo, Re, Nb) exhibit remarkable synergism in activity and selectivity, but the active sites remain poorly understood. Here, we examine the influence of oxide loading on PtMO_x inverse catalysts and introduce a high-pressure wash treatment to leach the excess oxide from carbon and optimize their structure. The findings reveal a saturation sub-monolayer MO_x coverage with 2D atomic structure on Pt that is crucial for performance; excessive loading leads to nanocrystalline of lower activity, and low loading exposes unselective metal sites. Wash treatment selectively removes MO_x from carbon, enhances their dispersion on Pt, and improves, in most cases, the performance. Tuning the inverse structure advances structure-reactivity understanding.

Decomplexation of heavy metal-organic complexes dominated by reactive oxygen species (ROS) oxidation had attracted extensive attention. Nanospace confinement is a novel strategy to enhance pollutant removal due to its regulation on ROS transformation and local accelerated dynamics. Herein, nano-confined Fe₂O₃ catalyst supported by carbon nanotubes (Fe₂O₃-in-CNTs) was synthesized, and it displayed obvious synergistic effects on decomplexation of Cu-EDTA complex in a non-thermal plasma (NTP) process. Cu-EDTA decomplexation efficiency reached 98.8% within 20 min in the NTP/Fe₂O₃-in-CNTs system, and the corresponding kinetic constant was 4.5 and 2.5 times as that in single NTP and unconfined systems, respectively. Based on experimental and theoretical results, nanospace confinement induced electron localization around Fe and C atoms and rearrangement of orbital electrons, favoring strongly oxidative Fe^Ⅳ formation and catalytic decomposition of H₂O₂ and O₃. Nanospace confinement made Cu-EDTA decomplexation process transform from radical pathway to non-radical pathway. Cu-EDTA decomplexation pathways in the NTP/Fe₂O₃-in-CNTs were proposed.

Construction of heterogeneous transmission interfaces that spatially separate Coulomb-bound electron-hole pairs in semiconductors allows exceptional control over optoelectronic properties, thereby enhancing the efficiency of solar energy conversion. In this study, we propose an effective photocatalyst for full water splitting named MS/BOC-x/Pd, comprising atomic layer of MoS₂ bonded to defect-rich BiOCl, and a non-plasmonic Pd oxidation co-catalyst is exclusively assembled on the sides to form a strong electronic coupling and maximize the trapping of holes. The presence of the Mo-S-Bi motif promotes rapid charge migration, resulting in impressive rates of H₂ and O₂ formation (165 and 9.17 μmol g⁻¹ h⁻¹, respectively), without the requirement of sacrificial agents or sensitizers. Through experimental and theoretical investigations, we discovered that the occupation of sulfur atoms in oxygen vacancies extends the overlap of surface charges, thereby facilitating the separation of inner/interfacial electron-hole pairs. The Mo-S-Bi bond provides directional guidance for charge transfer to the surface redox sites. These findings provide valuable insights for the future design of highly efficient photocatalysts for solar energy conversions.