Methane (CH4) is difficult to convert to upgraded fuels or chemicals because of the strength of the C-H bonds. Its activation and reforming with CO2 to syngas or with H2O to produce hydrogen, as well as its direct oxidation to methanol, is increasingly important because CH4 is a potent greenhouse gas. Ni at low loadings on CeO2 are active for CH4 activation at room-temperature and for these methane conversion reactions [1,2]. Revealing the nature of the active sites in such systems is paramount to a rational design of improved catalysts. Here we show that the most active sites are Ni atoms in clusters at step edges on the CeO2 surface, with a small size. We show that the size and morphology of the supported nanoparticles together with strong Ni−support bonding and charge transfer at the step edge are key to the high catalytic activity towards methane activation, allowing much better activity than expected from earlier linear scaling relations [3,4]. The emphasis is here put on theoretical studies in combination with experiments using ambient pressure X-ray photoelectron spectroscopy, adsorption calorimetry and surface analysis measurements.

The nature of the active sites on Ni/CeO2 catalysts for methane conversions

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.