Highly Selective Photothermal CO2-to-CO Conversion via RWGS over Ordered Mesoporous Ni/Silica Catalysts

Abstract

CO2 hydrogenation via reverse water–gas shift (RWGS) reaction is a promising route for CO2 utilization and CO production, but conventional Ni-based catalysts typically require high temperatures, leading to particle sintering and deactivation. Herein, La2O3-promoted Ni catalysts supported on ordered mesoporous SBA-16 are developed for photothermal RWGS via a simple impregnation method. The optimized 10Ni–10La2O3–SBA-16 catalyst achieves 71% CO2 conversion and 99% CO selectivity at 500 °C and atmospheric pressure, while delivering a CO production rate of 30.56 mmol gcat–1 h–1 with 96% selectivity at a WHSV of 120,000 mL gcat–1 h–1. Moreover, stable performance is maintained over 100 h on stream with negligible loss of CO selectivity. In situ XPS and DRIFTS analyses suggest light-induced interfacial electronic redistribution and possible involvement of carbonate/formate-related surface intermediates. Overall, this work highlights an effective catalyst design strategy for an efficient and durable photothermal RWGS.