cs9b02609_si_002.mov (14.61 MB)
Electrocatalytic Hydrogen Evolution in Neutral pH Solutions: Dual-Phase Synergy
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posted on 2019-08-23, 14:40 authored by Xiaohong Xie, Miao Song, Luguang Wang, Mark H. Engelhard, Langli Luo, Andrew Miller, Yayun Zhang, Lei Du, Huilin Pan, Zimin Nie, Yuanyuan Chu, Luis Estevez, Zidong Wei, Hong Liu, Chongmin Wang, Dongsheng Li, Yuyan ShaoElectrolysis in neutral
pH solutions (e.g., wastewater and seawater)
presents a transformative way for environmentally friendly, cost-effective
hydrogen production. However, one of the biggest challenges is the
lack of active, robust hydrogen evolution reaction (HER) catalysts.
Herein, we present a catalyst with dual-active sites of MoP2 and MoP, which function synergistically to promote HER in neutral
pH solutions. In our microbial electrolysis cell (MEC) test, which
uses neutral pH wastewater as feedstock, this catalyst delivers an
average HER current density of 157 A mcathode‑surface‑area–2, higher than Pt catalyst (145 A mcathode‑surface‑area–2)with the same amount of catalyst loading,
∼5 times higher than the state-of-art Pt group metal-free catalysts
in MECs. Our catalyst also outperforms Pt in natural seawater with
∼10% higher and more stable HER current density. The fundamental
reason for the enhanced HER performance is identified to be the synergy
between MoP2 and MoP phases, with MoP2 promoting
H2O dissociation and MoP efficiently converting Had into H2.