title: Molecular metal-Nx centres in porous carbon for electrocatalytic hydrogen evolution.
abstract: Replacement of precious platinum with efficient and low-cost catalysts for electrocatalytic hydrogen evolution at low overpotentials holds tremendous promise for clean energy devices. Here we report a novel type of robust cobalt-nitrogen/carbon catalyst for the hydrogen evolution reaction (HER) that is prepared by the pyrolysis of cobalt-N4 macrocycles or cobalt/o-phenylenediamine composites and using silica colloids as a hard template. We identify the well-dispersed molecular CoNx sites on the carbon support as the active sites responsible for the HER. The CoNx/C catalyst exhibits extremely high turnover frequencies per cobalt site in acids, for example, 0.39 and 6.5 s(-1) at an overpotential of 100 and 200 mV, respectively, which are higher than those reported for other scalable non-precious metal HER catalysts. Our results suggest the great promise of developing new families of non-precious metal HER catalysts based on the controlled conversion of homogeneous metal complexes into solid-state carbon catalysts via economically scalable protocols.
authors.affiliation: Max-Planck-Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
authors.forename: Hai-Wei
authors.initials: HW
authors.lastname: Liang
authors.affiliation: Max-Planck-Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Brüller
authors.affiliation: Max-Planck-Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.|Department of Chemistry and Food Chemistry &Center for Advancing Electronics Dresden (cfaed), Technische Universität Dresden, Mommsenstrasse 4, 01062 Dresden, Germany.
authors.forename: Renhao
authors.initials: R
authors.lastname: Dong
authors.affiliation: Department of Chemistry and Food Chemistry &Center for Advancing Electronics Dresden (cfaed), Technische Universität Dresden, Mommsenstrasse 4, 01062 Dresden, Germany.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Chemistry and Food Chemistry &Center for Advancing Electronics Dresden (cfaed), Technische Universität Dresden, Mommsenstrasse 4, 01062 Dresden, Germany.
authors.forename: Xinliang
authors.initials: X
authors.lastname: Feng
authors.affiliation: Max-Planck-Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Müllen