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Anion-exchange membrane fuel cells (AEMFCs) are promising clean energy devices of high efficiency; however, their large-scale applications suffer from high cost and/or poor activity of electrocatalysts, especially at the anode. Herein, an electrocatalyst composed of NiMo nanoparticles (≈50 nm) in situ anchored on N-doped carbon rods (denoted as NMNC) has been synthesized by a facile calcination method. The as-prepared NMNC catalyst shows an especially high hydrogen oxidation reaction (HOR) activity (3.23 mA cm −2 at 0.10 V vs reversible hydrogen electrode (RHE)), excellent stability during 10,000 cycles within −0.10 to 0.50 V vs RHE, and extraordinarily high CO tolerance in a 0.1 M KOH electrolyte. Particularly, the doping of Mo atoms into Ni lattices of the electrocatalyst results in Ni lattice distortion and well-regulated graphitization degree of the carbon matrix, contributing to the enhanced reducibility and accelerated HOR reaction kinetics. This facilely synthesized NMNC electrocatalyst of enhanced HOR activity is expected to serve as a promising anodic electrocatalyst for AEMFCs.

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The sub-zero start-up capability remains as a technical barrier for large-scale adoption of proton exchange membrane fuel cell (PEMFC) vehicles; the situation is even worse when carbon-based (i.e. graphite) bipolar plates, with a larger heat capacity, are used. Herein, we develop an alternate hydrogen pump (AHP) method, which enables successful start-up of a graphite-bipolar-plate (GBP) PEMFC from −30°C. By applying an alternate voltage to both sides of the PEMFC under H 2 atmosphere, the AHP method warms up the PEMFC using heat generated mainly from ohmic polarization and eliminates the hazard of super-cooled water freezing. Additionally, The AHP method causes minor changes of the PEMFC system. The energy efficiencies of the AHP method are analyzed and further improvements are proposed.

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