Natural halloysite nanotubes supported Ru as highly active catalyst for photothermal catalytic CO2 reduction

Photothermal catalytic CO2 reduction has emerged as a promising approach to efficiently utilize solar energy and reduce greenhouse gas emissions. Designing novel catalyst with high activity and selectivity is essential and challenging for practical applications of photothermal CO2 reduction. Herein, we report that natural halloysite nanotubes-supported Ru nanoparticles can boost the photothermal catalytic activity and selectivity of CO2 methanation under continuous flow conditions. The photothermal catalytic performance of optimized catalyst is up to 1704 mmolCH4 gcat−1 h−1 with 93% CH4 selectivity and 68% CO2 conversion, outperforming any other Ru-based catalysts in photothermal CO2 reduction. Mechanistic studies show that the outstanding catalytic performance is mainly attributed to the unique mesoporous tubular structure, excellent ability of light-to-heat and interfacial interactions between the halloysite nanotubes and Ru. This method of utilizing natural minerals as support provides a facile avenue for rational design of abundant and low-cost catalysts for efficient photothermal catalytic CO2 reduction. [Display omitted] •Halloysite nanotubes supported Ru boosts the photothermal catalytic CO2 methanation.•The optimized photothermal catalytic performance is up to 1704 mmolCH4 gcat−1 h−1.•The unique mesoporous tubular structure leads to excellent ability of light-to-heat.•The interfacial interactions of halloysite and Ru facilitate the catalytic activity.