The development of sustainable and environmentally friendly technologies for chemicals and energy supply is one of the most important challenges for our society today. Such technologies must address the mitigation of greenhouse gases emissions, in accordance with the Paris agreement signed in 2015. In this sense, the electrochemical reduction of CO2 to fuels and chemical feedstocks, using renewable electricity, provides a promising approach toward the artificial carbon recycling. The most crucial step for this technology is the development of efficient electrocatalysts capable of reducing CO2 to valuable hydrocarbon products at a low overpotential with high selectivity and stability.
In a recent article published in APL Materials*, scientists from IMDEA Energy and the University of Xiamen (China) reviewed the current developments and understanding of P-block post-transition metal (Sn, In, Pb, and Bi) based electrocatalysts for the electrochemical CO2 reduction. This group of electrocatalysts possesses a particularly high selectivity towards the reduction of CO2 to formate or formic acid, which is an important energy carrier for fuel cells and a raw material for the leather/textile and papermaking industrial fields. Therefore, CO2 recycling technologies based on this group of electrocatalysts have great potential to achieve industrial viability. The main focus of the review is on the current fundamental understanding of the surface chemistry, active sites, reaction mechanisms, and structure–activity relationships. The strategies to enhance the electrochemical activity, including morphology control, nanostructuring, defect engineering, doping, and alloying to modulate the electronic structure are also revised. Authors recognize that a multidisciplinary approach aiming at revealing the basic reaction mechanisms on catalysts surfaces and interfaces is key to the development of industrial processes to support a sustainable society. Such mechanistic studies may benefit from the current advances in the preparation of well-defined samples and in-situ spectroscopic techniques. This is important to draw more unambiguous conclusions on the experimental work and allows a better comparison with theoretical calculations that describe the electrocatalytic systems.
*Zhenni Yang, Freddy E. Oropeza, and Kelvin H. L. Zhang. “P-block metal-based (Sn, In, Bi, Pb) electrocatalysts for selective reduction of CO2 to formate” APL Materials 8, 060901 (2020) https://doi.org/10.1063/5.0004194
More info: Freddy E. Oropeza, Postdoctoral researcher, Photoactivated Processes Unit, email@example.com