ZnO incorporated hybrid catalytic proton exchange membrane for H2 generation
Jay N. Mishra, Priyanka A. Jha, Pardeep K. Jha, Pravin Kumar Singh, Suman Roy Choudhary, Prabhakar Singh
Abstract
Electrocatalytic proton exchange membranes (PEMs) represent a promising avenue for advancing the field of electrochemical energy conversion and storage by combining the proton-conducting function of PEMs with enhanced catalytic activity by incorporation of metal ions. Here, we systematically studied the ZnO-based metal-organic framework (MOF) and found the introduction of pegylated ZnO to the (diethyl methylamine)/(H2PO4) matrix to form the p-type conducting MOF membrane with a bandgap of 3.67 eV. This membrane not only has a high protonic conductivity of 0.027 S/cm at 300 K with a transference number >0.99 but also possesses high activity (Tafel slope ∼36 mV/decade). The high reaction kinetics supported by finite element modeling simulations shows its ability to produce efficient and sustainable hydrogen. Our results suggest high current density of 1.52 mA/cm2, a turn over frequency [H2 (s−1)] ∼0.474×1018s−1, and a stability of 168 h in neutral medium (pH = 7). This work will enhance new strategies for fabricating membranes with ionic liquid in order to get membranes with protonic conductivity along with high activity for large-scale water electrolysis.