Exsolved Ni nanoparticles acting as oxygen storage reservoirs and active sites for redox CH4 conversion
The growing demand for H2 and syngas requires the development of new, more efficient processes and materials for their production, especially from CH4 that is a widely available resource. One process that has recently received increased attention is chemical looping CH4 partial oxidation, which however, poses stringent requirements on material design, including fast oxygen exchange and high storage capacity, high reactivity towards CH4 activation and resistance to carbon deposition, often only met by composite materials. Here we design a catalytically active material for this process, based on exsolution from a porous titanate. The exsolved Ni particles act as both oxygen storage centres and as active sites for CH4 conversion under redox conditions. We control the extent of exsolution, particle size and population of Ni particles in order to tune the oxygen capacity, reactivity and stability of the system and, at the same time, obtain insights in parameters affecting and controlling exsolution.