Tailoring competitive adsorption sites of hydroxide ion to enhance urea oxidation-assisted hydrogen production

Jiali Lu; Wenjie Jiang; Rui Deng; Boyao Feng; Shibin Yin; Panagiotis Tsiakaras

doi:10.1016/j.jcis.2024.04.034

Tailoring competitive adsorption sites of hydroxide ion to enhance urea oxidation-assisted hydrogen production

J Colloid Interface Sci. 2024 Apr 5:667:249-258. doi: 10.1016/j.jcis.2024.04.034. Online ahead of print.

Authors

Jiali Lu¹, Wenjie Jiang¹, Rui Deng¹, Boyao Feng¹, Shibin Yin², Panagiotis Tsiakaras³

Affiliations

¹ Guangxi Key Laboratory of Electrochemical Energy Materials, School of Chemistry and Chemical Engineering, Guangxi University, 100 Daxue Road, Nanning 530004, China.
² Guangxi Key Laboratory of Electrochemical Energy Materials, School of Chemistry and Chemical Engineering, Guangxi University, 100 Daxue Road, Nanning 530004, China; Laboratory of Alternative Energy Conversion Systems, Department of Mechanical Engineering, School of Engineering, University of Thessaly, Pedion Areos 38834, Greece. Electronic address: yinshibin@gxu.edu.cn.
³ Laboratory of Electrochemical Devices based on Solid Oxide Proton Electrolytes, Institute of High Temperature Electrochemistry (RAS), Yekaterinburg 620990, Russian Federation; Laboratory of Alternative Energy Conversion Systems, Department of Mechanical Engineering, School of Engineering, University of Thessaly, Pedion Areos 38834, Greece. Electronic address: tsiak@uth.gr.

PMID: 38636226
DOI: 10.1016/j.jcis.2024.04.034

Abstract

Alloys with bimetallic electron modulation effect are promising catalysts for the electrooxidation of urea. However, the side reaction oxygen evolution reaction (OER) originating from the competitive adsorption of OH^- and urea severely limited the urea oxidation reaction (UOR) activity on the alloy catalysts. This work successfully constructs the defect-rich NiCo alloy with lattice strain (PMo-NiCo/NF) by rapid pyrolysis and co-doping. By taking advantage of the compressive strain, the d-band center of NiCo is shifted downward, inhibiting OH^- from adsorbing on the NiCo site and avoiding the detrimental OER. Meanwhile, the oxygenophilic P/Mo tailored specific adsorption sites to adsorb OH^- preferentially, which further released the NiCo sites to ensure the enriched adsorption of urea, thus improving the UOR efficiency. As a result, PMo-NiCo/NF only requires 1.27 V and -57 mV to drive a current density of ±10 mA cm^-2 for UOR and hydrogen evolution reaction (HER), respectively. With the guidance of this work, reactant competing adsorption sites could be tailored for effective electrocatalytic performance.

Keywords: Alloy catalyst; Co-doping; Competing adsorption; Lattice strain; Urea oxidation reaction.