Sulfur-anchoring synthesis of platinum intermetallic nanoparticle catalysts for fuel cells
Cheng-Long Yang, Lina Wang, Peng Yin, Jieyuan Liu, Ming‐Xi Chen, Qiangqiang Yan, Zheng-Shu Wang, Shi‐Long Xu, Shengqi Chu, Chunhua Cui, Huanxin Ju, Junfa Zhu, Yue Lin, Jianglan Shui, Hai‐Wei Liang
Abstract
Atomically ordered intermetallic nanoparticles are promising for catalytic applications but are difficult to produce because the high-temperature annealing required for atom ordering inevitably accelerates metal sintering that leads to larger crystallites. We prepared platinum intermetallics with an average particle size of <5 nanometers on porous sulfur-doped carbon supports, on which the strong interaction between platinum and sulfur suppresses metal sintering up to 1000°C. We synthesized intermetallic libraries of small nanoparticles consisting of 46 combinations of platinum with 16 other metal elements and used them to study the dependence of electrocatalytic oxygen-reduction reaction activity on alloy composition and platinum skin strain. The intermetallic libraries are highly mass efficient in proton-exchange-membrane fuel cells and could achieve high activities of 1.3 to 1.8 amperes per milligram of platinum at 0.9 volts.