Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Nat Commun. 2019 Mar 20;10(1):1278. doi: 10.1038/s41467-019-09290-y.
Although single-atomically dispersed metal-N on carbon support (M-NC) has great potential in heterogeneous catalysis, the scalable synthesis of such single-atom catalysts (SACs) with high-loading metal-N is greatly challenging since the loading and single-atomic dispersion have to be balanced at high temperature for forming metal-N. Herein, we develop a general cascade anchoring strategy for the mass production of a series of M-NC SACs with a metal loading up to 12.1 wt%. Systematic investigation reveals that the chelation of metal ions, physical isolation of chelate complex upon high loading, and the binding with N-species at elevated temperature are essential to achieving high-loading M-NC SACs. As a demonstration, high-loading Fe-NC SAC shows superior electrocatalytic performance for O reduction and Ni-NC SAC exhibits high electrocatalytic activity for CO reduction. The strategy paves a universal way to produce stable M-NC SAC with high-density metal-N sites for diverse high-performance applications.
尽管单原子分散在碳载体上的金属-N（M-NC）在多相催化中具有巨大的潜力，但要大规模合成具有高负载金属-N 的单原子催化剂（SACs）仍然具有很大的挑战性，因为在高温下形成金属-N 时，负载量和单原子分散性必须平衡。在此，我们开发了一种通用的级联锚定策略，用于大规模制备一系列负载量高达 12.1wt%的 M-NC SAC。系统研究表明，金属离子的螯合、高负载时螯合物复合物的物理隔离以及在高温下与 N 物种的结合对于实现高负载 M-NC SAC 至关重要。作为一个例子，高负载 Fe-NC SAC 表现出优异的 O 还原电催化性能，而 Ni-NC SAC 则表现出高的 CO 还原电催化活性。该策略为制备具有高密度金属-N 位的稳定 M-NC SAC 开辟了一条通用途径，可用于多种高性能应用。
