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Wafer-Scale Si Nanoconed Arrays Induced Syngas in the Photoelectrochemical CO2 Reduction
摘要： Photoelectrochemical (PEC) CO2 reduction offers a promising way to carry out the CO2 sequestration and develop the carbon-neutral technology. Doped Si is by far one of the most technologically important semiconductors with high conductivity and narrow bandgap, potential for CO2 reduction. However, the previous reports on PEC CO2 reduction over Si electrodes were not involved with many nanostructures. Syngas, a kind of chemical feedstocks and a crucial intermediate for hydrocarbon fuels, is highly demanded for industry. Herein, we used a wafer-scale nanoconed Si arrays substrate to load the metallic nanoparticles (Au and Cu). Effective PEC CO2 reduction into syngas was achieved in the aqueous solution with no sacrificial reagents. In contrast, planar Si seldom generated CO under the same reactant environment. Our finding deepens the comprehension of PEC CO2 reduction over the nanostructured materials and gives an inspiration for rational design of the PEC catalysts towards solar-to-chemical conversion.
关键词： Si,photoelectrochemical (PEC),CO2 reduction,nanostructure,syngas
更新于2025-11-19 16:51:07
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Hydrogen production via a novel two-step solar thermochemical cycle based on non-volatile GeO2
摘要： Encouraged by recent advances in solar-chemical fuel production, a moderately high-temperature solar thermochemical cycle based on GeO2/Ge is investigated thermodynamically. Since the GeO2/Ge redox has a great oxygen exchange capacity and suffers unfavorable phase change at high temperature, methanothermal reduction is introduced to lower the operation temperature below melting point of redox. The calculated results indicate that reduction conditions of 875 K < T_red < 1200 K and CH4:GeO2 = 2:1 are conducive to achieving high selectivities of H2 and CO. As for the oxidation step, the H2O:Ge ratio of 8:1 is found abundant enough to ensure complete reoxidation of Ge. Isothermal and non-isothermal solar-to-fuel efficiency (η_solarfuel) are compared, where η_solarfuel of 0.47 and isothermal η_solarfuel of 0.28 respectively. In addition, the preferred site of CH4 adsorbing on GeO2 is predicted, and the calculated adsorption energy is lower than that of SnO2, indicating that GeO2 could be a suitable material for substrate before methanothermal reduction.
关键词： Non-volatile redox,Isothermal and nonisothermal operation,Syngas production,Hydrogen production,GeO2/Ge based solar-chemical cycle
更新于2025-09-23 15:23:52
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Photosensitizing single-site metal?organic framework enabling visible-light-driven CO2 reduction for syngas production
摘要： Photocatalytic CO2 reduction into syngas (CO and H2) is one of sustainable strategies for recycling CO2 into value-added products. Herein, a simple and effective two-step self-assembly process was developed to functionalize phosphorescent metal-organic framework (MOF) with single site catalyst. The resulting (Co/Ru)n-UiO-67(bpydc) supplied molecular platform to enable fast multielectron injection from photosensitizers (PSs) to Co-catalyst, leading to the first MOF-based composite photocatalyst for efficient syngas production with a yield of 13600 μmol·g?1 (H2 : CO = 2 : 1) in 16 h, 29.2-fold higher than that of its homogeneous counterpart. The H2/CO ratios can be well controlled by carefully adjusting the molar ratio of PS/catalyst in the MOF platform and the water content in the photocatalytic system. This work provides a prospective strategy for recycling CO2 into H2-rich syngas by merging PSs and single-site catalysts into a MOF platform.
关键词： Metal-organic framework,CO2 reduction,photosensitizer,photocatalyst,syngas
更新于2025-09-23 15:23:52
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AIP Conference Proceedings [Author(s) SolarPACES 2017: International Conference on Concentrating Solar Power and Chemical Energy Systems - Santiago, Chile (26–29 September 2017)] - Co-production of syngas and zinc via combined solar-driven biomass gasification and ZnO carbo-thermal reduction in a continuously-operated solar reactor
摘要： The solar thermochemical gasification of biomass with in-situ ZnO carbo-thermal reduction was carried out in a lab-scale (1.5 kW) continuously-fed solar reactor. The objective of this study was to demonstrate the feasibility of the combined process involving wood biomass gasification with ZnO as an oxidizing agent under continuous process operation for co-production of syngas and metallic Zn. A controlled mixture of biomass and ZnO particles was injected in a cavity-type receiver directly irradiated by concentrated solar radiation. The influence of temperature (1050-1250°C) on syngas production was experimentally investigated and compared to the case of a pyrolysis process (without any oxidizing agent). H2 production increased drastically, CO production tended also to increase, while CH4 and CO2 concentrations decreased when increasing the temperature. The global syngas production of the combined gasification and ZnO carbo-thermal reduction was higher in comparison with pyrolysis. Collected products at the reactor outlet indicated high Zn content, with low recombination to ZnO in the solid products. The energy content of the feedstock was upgraded by the solar power input in the form of both syngas and Zn, thus outperforming pyrolysis in addition to delivering higher syngas output per unit of feedstock.
关键词： ZnO carbo-thermal reduction,syngas,biomass,metallic Zn,solar thermochemical gasification
更新于2025-09-09 09:28:46
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Size effects of ZnO nanoparticles in bifunctional catalysts for selective syngas conversion
摘要： The oxide-zeolite (OX-ZEO) bifunctional catalyst design concept has shown promising potential for selectivity control in syngas conversion by separating CO activation and C-C coupling onto oxides and zeolites, respectively. However, the structural effects of the oxides are far from being understood. Herein, we take a single component ZnO as a probe oxide in combination with SAPO-34 as a composite catalyst for light olefins synthesis from syngas. The space time yield of hydrocarbons significantly increases as the ZnO crystal size decreases from 79 to 23 nm, which can be attributed to more active centers available over smaller particles with a higher specific surface area. The apparent TOF for formation of light olefins (TOFlight olefins) increases over smaller ZnO particles whereas TOFlight paraffins decreases, leading to an increased ratio of light olefins/light paraffins, which indicates that smaller particles benefit the formation of olefins. These results demonstrate that it is crucial to control the particle size of oxides to design more active and selective OX-ZEO catalysts for syngas conversion to olefins.
关键词： Light olefins,Size effects,Syngas conversion,Oxides,ZnO
更新于2025-09-04 15:30:14