Fine-tuning Cu–Co–Ce oxidation activity interface by unique microwave electromagnetic loss for boosting CO preferential oxidation in H2 steam

Construction of composite metal interfaces with synergistic catalysis is an important research field for CO preferential oxidation in H₂ steam (CO-PROX). Microwave electromagnetic loss can effectively compensate the thermal action on the active interface derived from metal-organic frameworks (MOFs). Herein, a trimetallic CuCoCe-MOF is derived to construct Cu–Co–Ce oxidation active interface oriented by magnetic, conduction and relaxation loss, which inhibit the high temperature deactivation due to sintering. Equipped with the tandem microwave pyrolysis, the intermediate CuCoCe/C fully exposes electromagnetic characteristic and heterogeneous interfaces. Subsequently, microwave strengthened CuCoCeO_x exhibits an excellent CO-PROX activity window with the more than 85% CO conversion within 80–210 °C. Besides, in-situ Raman and in-situ DRIFTs investigations demonstrate that the equilibrium of active interfacial oxygen vacancy via hydrogen is crucial for the temperature window broadening of CO-PROX. This work provides a route for the efficient conversion of microwave electromagnetic energy to enhance the active interface for synergistic catalysis.     

Co–Ni/WC-AC catalysts for dry reforming of methane: The role of Ni species

To improve the DRM reaction performance of the catalysts, a series of Co–Ni/WC-AC catalysts are prepared by impregnation using WC-AC as the support. The structural features of the fresh and spent catalysts are characterized by BET, XRD, H₂-TPR, XPS and TG. The results show that the introduction of Ni in the 20Co/WC-AC catalyst promotes the conversion of W species to WC. Further, WC enhances the interaction between the active metal and the support. Thus, the activity and sintering resistance of Co–Ni/WC-AC catalysts are improved. It is also found that the introduction of different ratios of Ni has a significant effect on the chemical environment (oxygen environment) on the catalyst surface.10Co–10Ni/WC-AC catalysts showed high surface O_α and O_β contents of 26% and 53%, respectively. The catalyst shows excellent catalytic performance. The conversion of CH₄ and CO₂ is stable at about 84% and 85% at 800 °C.