Weitao Gao , Qinan Yin , Jiayi Chen , Zhuangzhi Liu , Zeping Zhang , Jiapeng Lu , Yijie Lei , Hong Xu , Hongwu Ouyang , Yanan Yin , Cheng Wang
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引用次数: 0
Abstract
In the field of proton exchange membrane fuel cells (PEMFCs), short-side-chain (SSC) ionomers are widely considered to enhance the catalytic activity of the catalyst layer, but the mechanism of enhancement is controversial. In this work, the density functional theory (DFT) calculations and practical membrane electrode assemblies (MEAs) experiments were performed to explore the mechanism of the improved catalytic activity by SSC ionomers. The interactions between Pt representative crystal planes and low-molecular-weight model anions/PFSA fragments were investigated by DFT calculations, which revealed and divided the effects of sulfonic groups, ether groups, and side-chain structures on the adsorption energy and adsorption state. The calculations showed that the ether group of the short side chain has difficulty in interacting with the Pt surface, while the ether group around the midpoint of the long side chain could still interact with the platinum. Therefore, the ionomers having longer side chains more strongly block ORR. In practical catalyst layers, the SSC ionomer significantly improved the MEA performance especially at high voltages, and increased the rated power density by up to 56.3% compared with conventional Nafion®. This work provides a reference for developing desirable ionomers to enhance the catalytic activity of PEMFC catalyst layers.
期刊介绍:
The Chemical Engineering Journal is an international research journal that invites contributions of original and novel fundamental research. It aims to provide an international platform for presenting original fundamental research, interpretative reviews, and discussions on new developments in chemical engineering. The journal welcomes papers that describe novel theory and its practical application, as well as those that demonstrate the transfer of techniques from other disciplines. It also welcomes reports on carefully conducted experimental work that is soundly interpreted. The main focus of the journal is on original and rigorous research results that have broad significance. The Catalysis section within the Chemical Engineering Journal focuses specifically on Experimental and Theoretical studies in the fields of heterogeneous catalysis, molecular catalysis, and biocatalysis. These studies have industrial impact on various sectors such as chemicals, energy, materials, foods, healthcare, and environmental protection.