Pt Atomic Site-Engineered Redox Mediator Boosts Electrosynthesis of Formic Acid from Glycerol

Electrophilic oxygen-mediated non-electrocatalytic processes on Ni-based catalysts enable highly selective electrosynthesis of formic acid from glycerol. However, this process, usually mediated by dual mediators of Ni³⁺-O and Ni^2+δ-(OH)_ads, is significantly plagued by the high potential of Ni³⁺-O. Herein, we report a class of Pt atomic site-engineered Ni^2+δ-(OH)_ads redox mediators without Ni³⁺-O involvement for breaking the dual-mediator mechanism limitation, achieving efficient formic acid electrosynthesis from glycerol at remarkably low potential. We demonstrate that Pt atomic sites on Ni aerogels can promote Ni^2+δ-(OH)_ads generation, thereby circumventing the Ni³⁺-O pathway and favoring initial C─C bond cleavage and sequential hydrogen atom transfer of C₁ intermediates. The resultant Ni₉₃Pt₇ exhibits a remarkably low onset potential of only 1.25 V and a high efficiency of 250 C for ∼100% glycerol conversion, outperforming Ni aerogels (1.36 V, 300 C) and catalysts reported previously, along with excellent stability over 180 h. We further demonstrate the broad applicability of this atomic site-promoted redox mediator engineering for low-potential electrosynthesis of low-carbon compounds from other vicinal polyols.