Guangfu Li

A Highly Stable Anode, Carbon-Free, Catalyst Support Based on Tungsten Trioxide Nanoclusters for Proton-Exchange Membrane Fuel Cells

Durability is an important issue in proton-exchange membrane fuel cells (PEMFCs). One of the major challenges lies in the degradation caused by the oxidation of the carbon support under high anode potentials (under fuel starvation conditions). Herein, we report highly stable, carbon-free, WO(3) nanoclusters as catalyst supports. The WO(3) nanoclusters are synthesized through a hard template method and characterized by means of electron microscopy and electrochemical analysis. The electrochemical studies show that the WO(3) nanoclusters have excellent electrochemical stability under a high potential (1.6 V for 10 h) compared to Vulcan XC-72. Pt nanoparticles supported on these nanoclusters exhibit high and stable electrocatalytic activity for the oxidation of hydrogen. The catalyst shows negligible loss in electrochemically active surface area (ECA) after an accelerated durability test, whereas the ECA of the Pt nanoparticles immobilized on conventional carbon decreases significantly after the same oxidation condition. Therefore, Pt/WO(3) could be considered as a promising alternative anode catalyst for PEMFCs.

A Hard‐Template Method for the Preparation of IrO2, and Its Performance in a Solid‐Polymer‐Electrolyte Water Electrolyzer

Morphological control by SBA-15: The performance of catalysts for the oxygen evolution reaction (OER) depends strongly on their structural and morphological properties. An IrO(2) nanomaterial with a morphology suitable for the OER is prepared by using a synthetic scheme involving a zeolite template, and shows enhanced activity and stability compared to IrO(2) fabricated by the traditional Adams-fusion method.

Effect of gas diffusion electrode parameters on anion exchange membrane fuel cell performance

Abstract Focused on the optimization of the gas diffusion electrode (GDE) in an alkaline anion exchange membrane fuel cell (AAEMFC), PTFE content and catalyst loading in the catalyst layer (CL) were found to have a substantial effect on the cell performance and electrochemical kinetics. The i-V curves, open circuit voltage, cell resistance, in-situ electrochemical impedance spectroscopy and kinetics analysis have been used to evaluate the electrochemical properties of the fabricated GDEs. The results reveal that the optimum PTFE content in the CL of AAEMFC is 20%. Pt loading ranged from 0.2–1.0 mg/cm2 was also investigated as a vital parameter for three-phase boundary, CL conductivity and catalyst utilization. Ultimately, the highest peak power density of 213 mW/cm2 was achieved at 50 °C from the prepared GDE with Pt loading of 1.0 mg/cm2 on Pt/C and 20% PTFE in CL of AAEMFC. Considering the Pt-based catalyst effective utilization and cost, however, the platinum requirement can be diminished to close to 0.5 mg/cm2 in CLwithout significant performance loss.

Nickel/cobalt oxide as a highly efficient OER electrocatalyst in an alkaline polymer electrolyte water electrolyzer

Water electrolysis by an alkaline solid polymer electrolyte (APE) water electrolyzer is a promising approach for hydrogen production from water. In this work, Ni/Co oxides were prepared by a hydrothermal method, and used as a high-efficiency OER electrocatalyst in an APE water electrolyzer. The APE water electrolyzer assembled with the as-prepared Ni/Co oxides and home-made APE showed a nearly constant operating potential, ∼2.03 V @ 100 mA cm−2 in 1 wt% KHCO3 solution for about 550 h in a durability test, indicating the catalyst with good stability can meet the long-term durability requirements of the water electrolyzer. This result shows the practical application of Ni/Co oxides in an alkaline solid polymer electrolyte electrolyzer.