Gyan-Barimah Caleb, Mantha Jagannath Sai Pavan, Lee Ha-Young, Wei Yi, Shin Cheol-Hwan, Maulana Muhammad Irfansyah, Kim Junki, Henkelman Graeme, Yu Jong-Sung
Department of Energy Science and Engineering, Daegu Gyeongbuk Institute of Science & Technology (DGIST), Daegu, Republic of Korea.
Department of Chemistry, The University of Texas at Austin, Austin, TX, USA.
Nat Commun. 2024 Aug 15;15(1):7034. doi: 10.1038/s41467-024-51280-2.
Alloys of platinum with alkaline earth metals promise to be active and highly stable for fuel cell applications, yet their synthesis in nanoparticles remains a challenge due to their high negative reduction potentials. Herein, we report a strategy that overcomes this challenge by preparing platinum-magnesium (PtMg) alloy nanoparticles in the solution phase. The PtMg nanoparticles exhibit a distinctive structure with a structurally ordered intermetallic core and a Pt-rich shell. The PtMg/C as a cathode catalyst in a hydrogen-oxygen fuel cell exhibits a mass activity of 0.50 A mg at 0.9 V with a marginal decrease to 0.48 A mg after 30,000 cycles, exceeding the US Department of Energy 2025 beginning-of-life and end-of-life mass activity targets, respectively. Theoretical studies show that the activity stems from a combination of ligand and strain effects between the intermetallic core and the Pt-rich shell, while the stability originates from the high vacancy formation energy of Mg in the alloy.
铂与碱土金属的合金有望在燃料电池应用中具有活性且高度稳定，但由于其高负还原电位，在纳米颗粒中合成它们仍然是一项挑战。在此，我们报告了一种通过在溶液相中制备铂镁（PtMg）合金纳米颗粒来克服这一挑战的策略。PtMg纳米颗粒呈现出独特的结构，具有结构有序的金属间化合物核心和富含Pt的壳层。作为氢氧燃料电池阴极催化剂的PtMg/C在0.9V时表现出0.50 A mg的质量活性，在30000次循环后略有下降至0.48 A mg，分别超过了美国能源部2025年的初始寿命和寿命末期质量活性目标。理论研究表明，活性源于金属间化合物核心与富含Pt的壳层之间的配体和应变效应的结合，而稳定性则源于合金中Mg的高空位形成能。
