Yongqi Liu,Shasha Chu,Yuebing Xu,Xinyu Chen,Hao Zhou,Jinlin Li,Yanjie Ren,Xintai Su
Upcycling Cr-containing sulfate waste into catalysts for CO2hydrogenation reaction benefits both pollution mitigation and economic sustainability. In this study, FeCrO3/Fe2O3catalysts were successfully prepared by a simple hydrothermal method using Cr-containing sodium sulfate (Cr-SS) as a Cr source for efficient conversion and stable treatment of Cr. The removal rate of Cr in Cr-SS can reach 99.9% at the optimized hydrothermal conditions. When the synthesized catalysts were activated and used for the CO2hydrogenation reaction, a 50% increase in CO2conversion was achieved compared with the catalyst prepared by impregnation with a comparable amount of Cr. According to the extraction and risk assessment code (RAC) of the Reference Office of the European Community Bureau (BCR), the synthesized FeCrO3/Fe2O3is risk-free. This work not only realizes the detoxification of the Cr-SS but transfers Cr into stable FeCrO3for application in a catalytic field, which provides a strategy for the harmless disposal and resource utilization of Cr-containing hazardous waste.
Lin Zhang,Xingda An,Kai Feng,Juan Li,Jingjing Liu,Jinxing Chen,Chaoran Li,Xiaohong Zhang,Le He
The interest in introducing light into heterogeneous catalysis is driven not only by the urgent need of replacing fossil energy but also by the promise of controlling product selectivity by light. The product selectivity differences observed in recent studies between light and dark reactions are often attributed to photochemical effects. Here, we report the discovery of a non-photochemical origin of selectivity difference, at essentially the same CO2 conversion rate, between photothermal and thermal CO2 hydrogenation reactions over a Ru/TiO2–x catalyst. While the presence of the photochemical effect from ultraviolet light is confirmed, it merely enhances the catalytic activity. Systematic investigation reveals that the gradual formation of an adsorbate-mediated strong metal–support interaction under catalytic conditions is responsible for the variation in the catalytic selectivity. We demonstrate that differences in product selectivity under light/dark reactions do not necessarily originate from photochemical effects. Our study refines the basis for determining photochemical effects and highlights the importance of excluding non-photochemical effects in mechanistic studies of light-controlled product selectivity.
Photothermal catalysis is a promising strategy for converting CO2 into high value-added chemical feedstocks. Its current major challenges lie in improving CO2 conversion efficiency and product selectivity. In this work, a series of Cu/TiO2 core–shell catalysts were prepared using the hard template method. The Cu10/TiO2 catalyst exhibited excellent performance for the photothermal conversion of CO2 to CO in the presence of H2 under Xe lamp irradiation (CO2 conversion, 30.6%; CO selectivity, ∼100%; CO maximum yield, 87.1 mmol h−1 gcat−1). Results indicated that the Cu/TiO2 catalyst has a good photo-to-thermal conversion ability based on the significant LSPR effect, and the existence of hot electrons makes the reaction follow the carbonate pathway efficiently. This article successfully achieves efficient CO2 reduction under inexpensive and non-toxic conditions. In addition, it also provides unique insights into the study of the LSPR effect in the field of photothermal catalysis.