In situ constructing of ultrastable ceramic@graphene core-shell architectures as advanced metal catalyst supports toward oxygen reduction

• 来源期刊: 能源化学
• 年，卷（期）: 2017,（6）
• 页码范围: 1160-1167
• 页数: 8页
• 语种: 英文

摘要

The changeable structure of 2D graphene nanosheets makes the Pt-based nanoparticles (NPs) possess a low efficiency toward oxygen reduction reaction (ORR) and a short lifetime for proton exchange membrane fuel cells.Thus,a unique TiC@graphene core-shell structure material with low surface energy is designed and prepared by an in situ forming strategy,and firstly applied as a stable support of Pt NPs.The as-prepared Pt/GNS@TiC catalyst presents a high activity.Especially,its ORR stability is remarkably improved.Even after 15000 potential cycles,the half-wave potential and mass activity toward ORR have almost no change.This can be attributed to that the graphene nanosheet existing in a sphere shape effectively avoids the restacking or folding caused by the giant surface tension in 2D graphene nanosheets,impeding the decrease of the triple-phase boundary on Pt NPs.Significantly,the power density of fuel cells with our novel catalyst reaches 853 mV cm-2 under a low Pt loading (0.25 mgPt cm-2) and H2/Air conditions.These indicate the new ceramic@graphene core-shell nanocomposite is a promising application in fuel cells and other fields.