As the result, this interface leads to the previously unachieved proton exchange membrane fuel cell performance on both the catalyst utilization (75% vs.
In this work, this ionomer/catalyst interface has been engineered utilizing the electrostatic attraction between positively charged catalyst and negatively charged ionomer particles in a catalyst ink and preserved into a solid catalyst layer. Building such an interface is a long-standing challenge due to the lack of interaction between the ionomer and catalyst particles, resulting in large ionomer agglomerates and inhomogeneous ionomer coverage over the catalyst nanoparticle, consequently, poor fuel cell performance. To translate the high RDE performance of catalyst into MEA, the design of an ideal ionomer/catalyst interface is proposed: a thin, conformal ionomer film covers the maximum surface of a Pt nanoparticle and thus simultaneously maximizes catalyst utilization, (i.e., high mass activity and electrochemical active surface area) and O2 diffusion rate (i.e., high current density performance) without compromising proton conduction. The high intrinsic catalyst activity exhibited on a rotating disk electrode (RDE) is rarely realized in the membrane electrode assembly (MEA), which is the long-standing challenge for PEMFC and causes low catalyst utilization.
The biggest obstacle to the widespread implantation of polymer electrolyte membrane fuel cells (PEMFCs) is the cost, primarily due to the use of platinum catalysts.
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