Electrochemical Hydrogen Separation and Recovery by Non‐Platinum Group Metal Anode Catalyst (α‐MoO ₃ ) on High‐Temperature Proton Exchange Membrane Fuel Cell Stack

ABSTRACT The high‐temperature proton exchange membrane fuel cell (HT‐PEMFC) is a promising, clean, and highly efficient method for hydrogen recovery from plasma pyrolysis assembly (PPA) effluent, which requires an efficient electrochemical hydrogen pumping assembly that can tolerate carbon monoxide and limit side reactions with acetylene. A Platinum Group Metal (PGM) catalyst yields good durability for PEMFCs but poses a challenge due to its high cost and low tolerance to toxic gases. Tremendous effort is needed to develop non‐PGM catalysts with improved performance, durability, and hydrogen recovery. In this work, we report a new mesoporous MoO ₃ anode catalyst that exhibits dual activity of HER and HOR, a state‐of‐the‐art among Platinum (Pt)‐free anode materials. The MoO ₃ catalyst displayed promising HER activity at a low overpotential of −120 mV vs RHE and showed comparable HOR activity (5.3 mW cm ⁻² ) with a platinum catalyst (8.8 mW cm ⁻² ), using Nafion and Celtec‐P membranes under H ₂ /air conditions. In H ₂ CO/C ₂ H ₂ /air conditions at 150°C, the MoO ₃ catalyst displayed hydrogen recovery of 43% using Nafion. In 46 h, it exhibited a constant 2.3% recovery using Celtec‐P membrane, whereas the Pt‐catalyst decreased from 18 to 0.6%. The results indicate a sustainable and cost‐effective fuel cell system without compromising electrochemical efficiency.