Self‐Powered Electrocatalytic Aldehyde Reforming Fuel Cell for Sustainable H2 Generation with ~200% Faradaic Efficiency

Formaldehyde (HCHO), a promising yet enigmatic hydrogen carrier, presents both an intriguing opportunity and a formidable challenge to unlock its full potential of conversion and hydrogen (H2) generation while safeguarding environmental sustainability. This study rises to the challenge by pioneering a hybrid acid/alkali formaldehyde hydrogen production fuel cell (h‐AAFHFC), an integrated system that integrates anodic partial electro‐reforming of aldehydes at low potential with the cathodic hydrogen evolution reaction (HER). The device introduces a new self‐powered paradigm for H2 generation, featuring high Faradaic efficiency (FE), co‐generation of electricity and acetate, and seamless synergy with renewable energy sources, all while achieving zero carbon dioxide emissions. The h‐AAFHFC attains an open‐circuit voltage of 1.11 V and a peak power density of 94 mW cm‐2, enabling simultaneous H2 production at both electrodes with an extraordinary FE of approximately 200%. This breakthrough marks a transformative shift, moving from traditional electricity‐driven systems to self‐sustaining H2 generation. Our work lays the foundation for an eco‐friendly, sustainable approach to H2 production, advancing the transition toward a carbon‐neutral energy future.