Chromium-Doped Nickel Oxide and Nickel Nitride Mediate Selective Electrocatalytic Oxidation of Sterol Intermediates Coupled with H2 Evolution

Replacing the oxygen evolution reaction (OER) with the thermodynamically favorable electrooxidation of organics is considered a promising approach for the simultaneous production of hydrogen (H-2) and high-value chemicals. However, exploring and optimizing efficient electrocatalysts remains a challenge for large-scale production of value-added steroid carbonyl and H-2. Herein, Cr-NiO/GF and Cr-Ni3N/GF (GF: graphite felt) electrocatalysts were designed as anode and cathode for the production of steroid carbonyls and H-2, respectively. The cooperative Cr-NiO and ACT (4-acetamido-2,2,6,6-tetramethyl-1-piperidine-N-oxyl) electrocatalyst can be extended to the electrooxidation of a series of steroid alcohols to the corresponding aldehydes. Additionally, Cr-Ni3N displays superior electrocatalytic activity for hydrogen evolution reaction (HER), with a low overpotential of 35 mV to deliver 10 mA cm(-2). Furthermore, the system coupled with anodic electrooxidation of sterol and cathodic HER exhibited excellent performance with high space-time yield of 48.85 kg m(-3) h(-1) for steroid carbonyl and 1.82 L h(-1) for H-2 generation in a two-layer stacked flow cell. Density Functional Theory (DFT) calculations indicated that Cr doping effectively stabilizes ACTH on the NiO surface, and ACTH molecule could be captured via the ketonic oxygen interaction with Cr, resulting in excellent electrocatalytic activity. This work develops a novel approach to the rational design of efficient electrocatalysts for the simultaneous production of H-2 and large-scale value-added pharmaceutical carbonyl intermediates.