Favoring Product Desorption by a Tailored Electronic Environment of Oxygen Vacancies in SrTiO3 via Cr Doping for Enhanced and Selective Electrocatalytic CO2 to CO Conversion

Paras Kalra; Dibyajyoti Ghosh; Pravin P Ingole

doi:10.1021/acsami.3c04190

Favoring Product Desorption by a Tailored Electronic Environment of Oxygen Vacancies in SrTiO₃ via Cr Doping for Enhanced and Selective Electrocatalytic CO₂ to CO Conversion

ACS Appl Mater Interfaces. 2023 Jun 28;15(25):30187-30198. doi: 10.1021/acsami.3c04190. Epub 2023 Jun 14.

Authors

Paras Kalra¹, Dibyajyoti Ghosh^{1

2}, Pravin P Ingole¹

Affiliations

¹ Department of Chemistry, Indian Institute of Technology Delhi, New Delhi 110016, India.
² Department of Materials Science and Engineering, Indian Institute of Technology Delhi, New Delhi 110016, India.

PMID: 37314759
DOI: 10.1021/acsami.3c04190

Abstract

The electrochemical CO₂ reduction reaction (ECO₂RR) into value-added products is crucial to address the herculean task of CO₂ mitigation. Several efforts are being made to develop active ECO₂RR catalysts, targeting enhanced CO₂ adsorption and activation. A rational design of ECO₂RR catalysts with a facile product desorption step is seldom reported. Herein, ensuing the Sabatier principle, we report a strategy for an enhanced ECO₂RR with a faradaic efficiency of 85% for CO production by targeting the product desorption step. The energy barrier for product desorption was lowered via a tailored electronic environment of oxygen vacancies (O_vac) in Cr-doped SrTiO₃. The substitutional doping of Cr³⁺ for Ti⁴⁺ into the SrTiO₃ lattice favors the generation of more O_vac and modifies the local electronic environment. Density functional theory analysis evinces the spontaneous dissociation of COOH^# intermediates over O_vac and lower CO intermediate binding on O_vac reducing the energy demand for CO release due to Cr doping.

Keywords: ab initio simulation; desorption; doping; electrochemical CO2 reduction; free energy calculations; oxygen vacancies; strontium titanate; tailored electronic environment.