Yating Hu1,2, Changjian Li1, Shibo Xi3, Zeyu Deng1, Ximeng Liu1, Anthony K Cheetham1,4, John Wang1. 1. Department of Materials Science and Engineering National University of Singapore 9 Engineering Drive 1 Singapore 117574 Singapore. 2. Function Hub Hong Kong University of Science and Technology (Guangzhou) S&T Building, Nansha IT Park Guangzhou 511458 China. 3. Institute of Chemical and Engineering Sciences Agency for Science, Technology and Research (ASTAR) 1 Pesek Road, Jurong Island Singapore 627833 Singapore. 4. Materials Research Laboratory University of California Santa Barbara CA 93106 USA.
Abstract
Although metal-organic frameworks (MOFs) are being widely used to derive functional nanomaterials through pyrolysis, the actual mechanisms involved remain unclear. In the limited studies to date, elemental metallic species are found to be the initial products, which limits the variety of MOF-derived nanomaterials. Here, the pyrolysis of a manganese triazolate MOF is examined carefully in terms of phase transformation, reaction pathways, and morphology evolution in different conditions. Surprisingly, the formation of metal is not detected when manganese triazolate is pyrolyzed in an oxygen-free environment. Instead, a direct transformation into nanoparticles of manganese nitride, Mn2N x embedded in N-doped graphitic carbon took place. The electrically conductive Mn2N x nanoparticles show much better air stability than bulk samples and exhibit promising electrocatalytic performance for the oxygen reduction reaction. The findings on pyrolysis mechanisms expand the potential of MOF as a precursor to derive more functional nanomaterials.
Although metal-organic frameworks (MOFs) n class="Chemical">are being widely used to derive functional nanomaterials through pyrolysis, the actual mechanisms involved remain unclear. In the limited studies to date, elemental metallic species are found to be the initial products, which limits the variety of MOF-derived nanomaterials. Here, the pyrolysis of a manganese triazolate MOF is examined carefully in terms of phase transformation, reaction pathways, and morphology evolution in different conditions. Surprisingly, the formation of metal is not detected when manganese triazolate is pyrolyzed in an oxygen-free environment. Instead, a direct transformation into nanoparticles of manganese nitride, Mn2N x embedded in N-dopedgraphiticcarbon took place. The electrically conductive Mn2N x nanoparticles show much better air stability than bulk samples and exhibit promising electrocatalytic performance for the oxygen reduction reaction. The findings on pyrolysis mechanisms expand the potential of MOF as a precursor to derive more functional nanomaterials.
Authors: Carsten Walter; Prashanth W Menezes; Steven Orthmann; Jona Schuch; Paula Connor; Bernhard Kaiser; Martin Lerch; Matthias Driess Journal: Angew Chem Int Ed Engl Date: 2017-12-18 Impact factor: 15.336