Promoted CO₂ Reforming with Bioethanol over TiO₂-Supported Photothermal Catalysts

Reducing the greenhouse gas CO₂ in the atmosphere and converting it into high-value-added syngas is regarded as a competitive strategy in line with green and sustainable development. Herein, a series of M/TiO₂ (M = Cu, Co, Ni) catalysts were developed for photothermal CO₂ reduction with bioethanol, and the synergistic mechanism between photocatalysis and thermocatalysis was deeply investigated. Systematic characteristics and photothermal ethanol dry reforming (EDR) testing results revealed the relevancy between catalytic behavior and microstructure properties of TiO₂-supported catalysts. Notably, the Ni/TiO₂ catalyst displayed superior catalytic behavior than Cu/TiO₂ and Co/TiO₂ counterparts, which mainly attributed to their abundant oxygen vacancies and stronger Ni–TiO₂ interaction. In addition, both the narrower band gap and higher light absorption ability directly promoted the Ni/TiO₂ catalyst possessing outstanding ethanol conversion (94.5%) and controllable H₂/CO ratio (0.65) at 450 ℃. Furthermore, the relatively less activation energy also determined that the Ni/TiO₂ sample possessed the fastest kinetic progression in the EDR process. Therefore, the Ni/TiO₂ catalyst exhibited the better photothermal catalytic activity compared with other 2 samples. We anticipate that photothermal synergy would offer good technical guidance to promote the conversion and utilization of greenhouse gas CO₂ under relatively low temperature environment.