Zhang, Wenzhe; Lin, Heyun; Wei, Yao; Zhou, Xuan; An, Yunlei; Dai, Yuanyuan; Niu, Qiang; Lin, Tiejun; Zhong, Liangshu

ACS CATALYSIS

2024, 14,

Zhang, Wenzhe; Lin, Heyun; Wei, Yao; Zhou, Xuan; An, Yunlei; Dai, Yuanyuan; Niu, Qiang; Lin, Tiejun; Zhong, Liangshu

Strong metal-support interaction (SMSI) is commonly observed for platinum-group metals on reducible oxide supports upon a high-temperature reduction (>= 500 degrees C). Herein, we show that the SMSI state can be constructed over a Ru/anatase-TiO2 catalyst using the CO2 hydrogenation reaction gas at a low temperature of similar to 210 degrees C, which could overturn the CO2 hydrogenation selectivity from 100% CH4 to >99% CO. It is revealed that the exposed metallic Ru nanoparticles promote CH4 formation via formate intermediates at temperatures <200 degrees C. Elevating the temperature under a H-2-containing atmosphere causes the evolution of active TiOx suboxide to form an encapsulated structure of Ru@TiOx, which changes the surface intermediate from formate to carboxy species during CO2 hydrogenation, thus leading to exclusive CO formation with long-term catalytic stability. The O-2-containing gas treatment of encapsulated Ru@TiOx could achieve the cyclic switch of product selectivity between CO and CH4. This work provides an effective strategy to modulate the SMSI state at a very low temperature.