Selective electrochemical methanol to formate conversion via direct CHO hydroxylation on Pt^δ+-Pt^δ- dipoles.

Abstract

The electrochemical upgrading of methanol to formate is constrained by CO poisoning from *CHO intermediate dehydrogenation, hindering its industrial application. Herein, we report that engineering atomically polarized Pt^δ+-Pt^δ- dipoles on Ti felt achieves a formate Faradaic efficiency of 99% at +0.9 V vs. RHE, which is better than that of commercial Pt/C (62%). Moreover, a formate production rate of 945 mmol g_Pt^-1 h^-1 is achieved with stable performance for more than 5 days at 100 mA cm^-2. These dipoles comprise spatially adjacent electron-deficient Pt^δ+ bonded to lattice O and electron-rich Pt^δ- coordinated to unsaturated Ti atoms working synergistically. The Pt^δ+ site dehydrogenates CH₃OH to *CHO, which adsorbs across the dipole in a side-on Pt^δ+-OHC-Pt^δ- bridging configuration. Within this configuration, Pt^δ- donates electrons via d→π* backdonation to the π* antibonding orbital of *CHO, steering its direct hydroxylation and generating electrostatic repulsion for rapid HCOOH desorption. This strategy reduces environmental impact by 88% and carbon emissions by 11% relative to conventional thermal routes, demonstrating the potential of dipole engineering for C₁ electrochemistry.