Industrially viable formate production with 50% lower CO2 emissions†

Abstract

The conventional production of formic acid is energy-intensive, requiring methanol and carbon monoxide reactions followed by hydrolysis under high temperature and pressure. Methanol electrochemical refinery (e-refinery) offers a sustainable alternative but faces challenges like high overpotential and competing oxygen evolution reaction (OER). This study presents Pt-nanoparticle-decorated Ni(OH)₂ as a breakthrough catalyst, achieving a significantly lower onset potential of 0.5 V vs. reversible hydrogen electrode (RHE) for methanol-to-formate conversion compared to previous reports (>1.35 V vs. RHE), while simultaneously generating hydrogen at the cathode. The platinum valence state is identified as an effective descriptor for formate faradaic efficiency, validated through experimental studies and density functional theory. Pt_1.05@Ni(OH)₂, featuring the highest platinum valence states among the catalysts studied, exhibits an exceptional formate faradaic efficiency of 78.8% and a high formate production rate of 1.3 mmol h⁻¹ mg_cat⁻¹ at 0.8 V vs. RHE. This approach reduces overpotential, eliminates OER, and cuts carbon dioxide emissions by over 50% compared to traditional methods. Moreover, economic analysis shows profitability from the fourth year at 50 mA cm⁻², supporting easier industrial adoption and low carbon dioxide emissions. These advancements offer a sustainable, energy-efficient, and economically viable method for formate production, advancing the commercialization of methanol e-refinery technology.