Enhancing the stability and activity by anchoring Pt nanoparticles between the layers of etched montmorillonite for oxygen reduction reaction

Proton exchange membrane fuel cells （PEMFCs） are rec- ognized as potential environmentally friendly power sour- ces owing to their high energy conversion efficiency and low pollutant emissions [1-4]. However, the insufficient electrocatalytic durability of Pt cathode catalysts remains one of the major obstacles for their wide applications [5-8]. The Pt cathode catalyst is predominantly operated under harsh potential fluctuations, particularly during start- up and shut-down cycles where the electrode potential can locally reach values up to 1.5 V [1, 6, 9, 10]. At such a high potential, both the corrosion of carbon support and the dissolution of Pt followed by particle growth due to Ost- wald ripening inevitably occur, leading to the degradation of catalytic performance [9, 11, 12]. To address this issue, the modification of the interaction between Pt NPs and carbon materials by decorating Pt NP surfaces with mole- cules or tuning the chemical and physical properties of the carbon supports have been developed. These approaches are proved to be efficient in suppressing the agglomeration and migration of Pt NPs [9, 13-18]. However, to meet the commercial requirement in stability at low Pt loading, further improvement is still needed and remains great challenges for the catalysis of oxygen reduction reaction （ORR）.