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 Ni-O and Ni-(OH), is significantly plagued by the high potential of Ni-O. Herein, we report a class of Pt atomic site-engineered Ni-(OH) redox mediators without Ni-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-(OH) generation, thereby circumventing the Ni-O pathway and favoring initial C─C bond cleavage and sequential hydrogen atom transfer of C intermediates. The resultant NiPt 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.