Selective Formate Production from the Electrochemical CO₂ Reduction Reaction of Surface Oxide-Modified InSn₄ Binary Catalysts

Abstract

The electrochemical CO 2 reduction reaction (CO 2 RR) which produces high value-added products is regarded as a prospective path toward carbon cycling. However, the challenges in the electrochemical CO 2 RR are its competition to the hydrogen evolution reaction (HER) and unsatisfied product selectivity. Therefore, the design and preparation of highly effective catalysts with low overpotential, high faradaic efficiency (FE), and high selectivity are key considerations for the development of the CO 2 RR technology. In this research, binary In−Sn catalysts with In/Sn atomic ratios of 3/1 and 1/1 have been prepared. In−Sn nanoparticles (NPs) are composed of In and InSn 4 with some surface In and Sn oxides. Sn addition enhances the partial current density of formate production during the CO 2 RR. In 3 Sn/C NPs show outstanding performance with a HCOOH FE of 92.6% and excellent durability for 10 h at −1.0 V. In addition, the comparison of the binary In 3 Sn/C and physical mixture (In/C and SnO 2 /C) highlights that In 4 Sn is responsible for the high activity and stability of formate conversion. This research provides guidelines for the design of CO 2 RR catalysts with high formate conversion by optimization of compositions and structures of InSn NPs.

Tin as a co-catalyst for electrocatalytic oxidation and reduction reactions

“…Thus, the presence of In(OH) 3 and especially InSn 4 phases is responsible for the high formate selectivity. 146 Many of the best performing catalysts consist of more than just the metals Sn 0 or In 0 ; oxide-based materials are often superior. While a great deal of effort has focused on the electroreduction of CO 2 in the form of indium, tin, and their oxides, few reports have focused on the study of tin-doped indium oxide (ITO) nanocrystals (NCs).…”

“…Thus, the presence of In(OH) 3 and especially InSn 4 phases is responsible for the high formate selectivity. 146…”

“…145 The bimetallic catalysts enable precise control of the surface electronic states and binding energies of the electrocatalysts compared to pure metal electrodes, resulting in improved catalytic activity and stability. 146…”

Metal Ce-Leaching Induced Structural Optimization of Bismuth Electrocatalyst for Enhanced CO2 Electroreduction

“…The dramatic increase in the consumption of fossil fuels leads to a rise in the concentration of CO 2 in the atmosphere. − Electrochemical CO 2 reduction reaction (CO 2 RR) has received a lot of attention as a promising technology that can not only reduce CO 2 accumulation, but also convert CO 2 into valuable chemicals and fuels at room temperature, including CO, formate, hydrocarbons, and alcohols. − Among them, formate is one of the most valuable electroreduction products due to the huge market demand for emerging applications such as rubber, textile, leather, pesticide, and pharmaceutical industries. − Moreover, it can be used as a source of hydrogen storage and transportation, as well as a fuel for direct formic acid fuel cells. − However, although formate is a two-electron product, the high activation energy of CO 2 and competitive hydrogen evolution (HER) of CO 2 RR still limit its application . Therefore, exploiting efficient catalysts with high selectivity and stability is significant.…”