Electrified CO2 Hydrogenation by in-situ Joule Heating: From metal skeleton catalysts to the thermo-electric catalytic mechanism

"Massive emissions of greenhouse gases (mainly CO2) are strongly linked to the current global warming and climate crisis. CO2 hydrogenation has emerged as one of the most promising approaches to reducing greenhouse effect by converting CO2 into value-added fuel or chemicals. While the reaction is still challenging due to the chemical inertness of CO2, the lack of efficient catalyst and high energy consumption for CO2 activation. This project proposes a new method of using in-situ Joule heating of metal skeleton catalyst to improve CO2 conversion and reduce energy consumption. The metal skeleton catalyst is heated by itself based on Joule's law when applying an electric current. Besides the Joule heat, it potentially increases oxygen vacancies and H* species for activating CO2, which produces the electro-catalytic effect. This new method performs the thermo-electric dual catalysis to promote CO2 conversion. Furthermore, in-situ Joule heating has a small hot zone and reduces energy loss. Owing to these advantages, this method has great application prospect. However, it has rarely been investigated, and the catalyst design and optimization, thermo-electric catalytic mechanism are not clear. To better use it, three work packages will be conducted in this project. The three-layer metal skeleton catalysts will be first synthesized and analyzed. Then, the properties of pulsed/continuous Joule heating (PJH/CJH), and their catalytic performances of CO2 hydrogenation to CO (RWGS) will be tested to establish catalyst structure-performance relationship. Thirdly, the thermo-electric catalytic mechanism will be elucidated by various Operando methodology (such as X-ray absorption fine structure (XAFS), Resonant X-ray inelastic scattering (RIXS)) and first-principles calculations. The research will serve as a critical technique in CO2 hydrogenation, hydrogen economy and green electricity storage (""Power to X""), which will power the carbon neutrality in the EU, UK and beyond."