Atomically Dispersed Platinum on Conjugated Polymers with Tailored Cation- Interactions and Microstructures for Hydrogen Evolution Electrocatalysis

Developing high-performance platinum (Pt) single atom catalyst with maximum metal-atom-utilization efficiency is of significance for water electrolysis, which demonstrates enormous potentials toward hydrogen evolution reaction (HER). In addition to stably immobilizing Pt single atoms on a support material, it is highly desired to elaborately tailor their coordination environments for achieving optimized HER performance. In this work, a general strategy is reported to develop advanced catalysts with Pt single atoms immobilized on conjugated polymers, where their coordination environments and HER activities can be readily tailored by adjusting the cation-pi interactions formed between the Pt single atoms and conjugated polymers. For the proof-of-concept study, polypyrrole (PPy), polyfuran (PFu), and polythiophene (PTh) with analogous molecular structures are investigated, where the N, O, and S heteroatoms in PPy, PFu, and PTh can affect their pi domains and induce different cation-pi interactions. Experimental and theoretical studies both suggest that the HER performance of the resulting catalysts follows the trend of Pt-1-PTh < Pt-1-PFu < Pt-1-PPy, which shows a correlation with their cation-pi interactions. Moreover, by utilizing the microstructure-tailorable property of conjugated polymers, PPy aerogel with enhanced specific surface area are prepared to support Pt single atoms, achieving substantial HER performance improvement.