Role of Ni in PtNi bimetallic electrocatalysts for hydrogen and value-added chemicals coproduction via glycerol electrooxidation

DOI: 10.1021/acscatal.2c03907

Authors: Hui Luo (Imperial College London) , Victor Y. Yukuhiro (State University of Campinas) , Pablo S. Fernández (State University of Campinas) , Jingyu Feng (Imperial College London; Queen Mary University of London) , Paul Thompson (ESRF) , Reshma R. Rao (Imperial College London) , Rongsheng Cai (University of Manchester) , Silvia Favero (Imperial College London) , Sarah J. Haigh (University of Manchester) , James R. Durrant (Imperial College London) , Ifan E. L. Stephens (Imperial College London) , Maria-Magdalena Titirici (Queen Mary University of London)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Acs Catalysis , VOL 5 , PAGES 14492 - 14506

State: Published (Approved)
Published: November 2022
Diamond Proposal Number(s): 28663 , 25476

Abstract: Pt-based bimetallic electrocatalysts are promising candidates to convert surplus glycerol from the biodiesel industry to value-added chemicals and coproduce hydrogen. It is expected that the nature and content of the elements in the bimetallic catalyst can not only affect the reaction kinetics but also influence the product selectivity, providing a way to increase the yield of the desired products. Hence, in this work, we investigate the electrochemical oxidation of glycerol on a series of PtNi nanoparticles with increasing Ni content using a combination of physicochemical structural analysis, electrochemical measurements, operando spectroscopic techniques, and advanced product characterizations. With a moderate Ni content and a homogenously alloyed bimetallic Pt–Ni structure, the PtNi2 catalyst displayed the highest reaction activity among all materials studied in this work. In situ FTIR data show that PtNi2 can activate the glycerol molecule at a more negative potential (0.4 VRHE) than the other PtNi catalysts. In addition, its surface can effectively catalyze the complete C–C bond cleavage, resulting in lower CO poisoning and higher stability. Operando X-ray absorption spectroscopy and UV–vis spectroscopy suggest that glycerol adsorbs strongly onto surface Ni(OH)x sites, preventing their oxidation and activation of oxygen or hydroxyl from water. As such, we propose that the role of Ni in PtNi toward glycerol oxidation is to tailor the electronic structure of the pure Pt sites rather than a bifunctional mechanism. Our experiments provide guidance for the development of bimetallic catalysts toward highly efficient, selective, and stable glycerol oxidation reactions.

Journal Keywords: glycerol oxidation; electrocatalysis; PtNi nanoparticles; glycerol adsorption; operando spectroscopy; product distribution

Subject Areas: Chemistry, Materials, Environment

Diamond Offline Facilities: Electron Physical Sciences Imaging Centre (ePSIC)
Instruments: E01-JEM ARM 200CF , I20-EDE-Energy Dispersive EXAFS (EDE)

Other Facilities: XMaS (BM28) at ESRF

Added On: 14/11/2022 09:00

Discipline Tags:

Earth Sciences & Environment Sustainable Energy Systems Energy Climate Change Physical Chemistry Catalysis Chemistry Materials Science Nanoscience/Nanotechnology

Technical Tags:

Spectroscopy X-ray Absorption Spectroscopy (XAS)