Photoelectrochemical Oxidation of Methane using Single Atom Catalysts

ended

Natural gas (primarily methane, CH4) is still a major energy source that is often simply flared into the atmosphere without being harnessed. As a cumulative result, unprecedented CH4 spikes have been reported lately in Earth’s atmosphere. Combined with the already existing Global warming concerns posed by other greenhouse gases such as CO2, CO, NOx, etc., CH4 abundance will lead to a worldwide catastrophe. Various attempts to convert and utilize CH4 into useful chemicals in mild reaction conditions have only seen limited success. In this proposal, we aim to target the CH4 molecule by fixing the CO2 molecule to produce acetic acid [CH3COOH, a high-value industrial chemical - the global acetic acid market attained a value of over 8.7 billion EUR in 2020 and is expected to grow at a compound annual growth rate (CAGR) of 5.5% from 2022 to 2027] via Photoelectrochemistry (PEC, using light and electricity) employing a new generation of heterogeneous catalysts called Single Atom Catalysts (SACs, containing abundantly available single transition metal atom embedded on transition metal oxide semiconductors that can rival catalytic efficacy of a well-defined homogeneous catalyst). To achieve this goal, we will mainly study (1) different band-energies of SACs using optical and electrochemical methods; (2) select and examine appropriate SACs with band energies that can enable CH4 oxidation and CO2 reduction; (3) examine their selectivity, efficiency, and recyclability through catalyst and reaction optimizations; (4) characterize the best performing SACs and (5) decipher the reaction mechanism with the aid of computational methods. We will disseminate the results through papers, conference presentations, public outreach events, social media, etc., while gaining several scientific and transferable skills required for career progress. A new pathway towards methane valorization is foreseen through this project, which can be highly attractive in an academic and industrial setting.