Bottom-up synthesis of MOF-derived hollow N-doped carbon materials for enhanced ORR performance

The search on low-cost, ultra-stable, and high-performance non-novel metal replacements to the Ptbased catalysts for oxygen reduction reaction (ORR) is of great urgency. Herein, a bottom-up method has been proposed to synthesize unique hollow N-doped carbon spheres (HNCSs) from an initial amorphous coordination polymer (CP) template-assisted route for the first time. HNCSs exhibit competitively comparable high electrocatalytic ORR activity, excellent reaction selectivity, and stronger long-term stability and negligible methanol crossover effect compared to the commercial Pt/C under the alkaline medium. Together with the other two reported carbonaceous ORR catalysts, including SCSs and NGPCs, our HNCSs possess the lowest Tafel slope of 65.7 mV dec(-1) which is close to Pt/C (62.6 mV dec(-1)), and show much enhanced ORR activity (J(L) = 5.34 mA cm(-2)) and stability (Retention = 96.5%, Time = 10 h). This CP-templated route for hollow carbon materials will shed light on a new synthetic strategy to prepare high-performance carbon-based and/or metal-free ORR catalysts. (c) 2019 Elsevier Ltd. All rights reserved.

寻找用于氧还原反应（ORR）的低成本、超稳定且高性能的非贵金属替代铂基催化剂迫在眉睫。在此，首次提出了一种自下而上的方法，从初始的无定形配位聚合物（CP）模板辅助途径合成独特的中空氮掺杂碳球（HNCSs）。在碱性介质中，与商业Pt/C相比，HNCSs表现出具有竞争力的相当高的电催化ORR活性、优异的反应选择性、更强的长期稳定性以及可忽略不计的甲醇渗透效应。与另外两种已报道的碳质ORR催化剂（包括SCSs和NGPCs）一起，我们的HNCSs具有最低的塔菲尔斜率，为65.7 mV dec⁻¹，接近Pt/C（62.6 mV dec⁻¹），并且显示出大大增强的ORR活性（J(L)=5.34 mA cm⁻²）和稳定性（保留率 = 96.5%，时间 = 10小时）。这种用于中空碳材料的CP模板途径将为制备高性能碳基和/或无金属ORR催化剂的新合成策略提供启示。（c）2019爱思唯尔有限公司。保留所有权利。