N-Doped Carbon-Encapsulated Cu@SS-Arg Catalyst for H2 Production from Aqueous-Phase Reforming of Ethanol: Toward Carbon-Neutral Energy Cycles

The development of high-performance catalysts for aqueous-phase reforming of ethanol (APRE) is essential for advancing sustainable hydrogen production and achieving carbon neutrality. Herein, we report a N-doped carbon-encapsulated Cu nanoparticle catalyst (Cu@SS-Arg), which enhances hydrogen selectivity and suppresses carbon-containing gas byproducts. The Cu@SS-Arg catalyst, which has been optimized, achieves a H2 production rate of 31.2 μmol/gcat/s with a H2 selectivity of 99.99% at 210 °C, while concomitantly reducing CO emissions in comparison to commercial precious metal catalysts. In situ DRIFTS and TPSR-MS analyses demonstrate that the Cu+/Cu0 active sites not only promote ethanol/water activation but also facilitate the C–H/O–H bond cleavage, thus favoring the ethanol dehydrogenation (via *CH3CH2O, *CH3CHO, and *CH3COOH intermediates), water dissociation (*H2O → *OH + *H) and carbon monoxide conversion (*CO + *OH → *CO2 + *H) pathways over C–C bond cleavage. This work presents a dual strategy for designing nonprecious metal catalysts that synergistically integrates structural stabilization with N-doping regulation. Together, these approaches enable sustainable and low-carbon production of hydrogen from renewable ethanol.