Heterophase engineering of SnO2/Sn3O4 drives enhanced carbon dioxide electrocatalytic reduction to formic acid
Jun Wu, Ying Xie, Shichao Du, Zhiyu Ren, Peng Yu, Xiuwen Wang, Guiling Wang, Honggang Fu
Abstract
Sn-based electrocatalysts have been gaining increasing attention due to their potential contribution in the conversion of CO 2 into HCOOH driven by sustainable energy sources; however, their actual capability to catalyze CO 2 reduction reaction (CO 2 RR) still cannot meet the requirements of commercial-scale applications. Therefore developing Sn-based catalyst is of vital importance. Herein, the sheet-like heterophase SnO 2 /Sn 3 O 4 with a high density of phase interfaces has been first engineered by a facile hydrothermal process, with Sn 3 O 4 as the dominant phase. The evidences from experiments and theoretical simulation indicate that the charge redistribution and built-in electric field at heterophase interfaces boost CO 2 adsorption and HCOO* formation, accelerate the charge transfer between the catalysts and reactants, and ultimately greatly elevate the intrinsic activity of the heterophase SnO 2 /Sn 3 O 4 towards CO 2 RR. Meanwhile, the in-situ generated porous structure and metal Sn during CO 2 RR improve the mass transmission within the interlayer volume and the conductivity of SnO 2 /Sn 3 O 4 . The heterophase SnO 2 /Sn 3 O 4 displays high activity and selectivity for CO 2 RR, achieving an improvement in CO 2 reduction current density, 88.3% Faradaic efficiency of HCOOH conversion at −0.9 V RHE , along with a long-term tolerance in CO 2 RR. This study demonstrates that heterophase interface engineering is an efficient strategy to regulate advanced catalysts for different applications.