Partial oxidation of methane to methanol catalyzed by single-atom noble metal (Rh, Pd or Pt) supported on doped mesoporous CeO2 (Ce1-xMxO2, M = Zr, Sn or La)

Abstract

The abundance, low cost and environmental concerns related to emission of methane into the atmosphere have intensified research for valorization of this gas in recent years. Currently, processes that efficiently convert methane to alcohols or olefins are complex and costly, because they require the intermediate step of reforming methane to synthesis gas (CO and H2). Due to the difficulties involved in the indirect route, conversion to alcohols and larger hydrocarbons by direct route and under mild reaction conditions has been extensively studied. One of the major products in the direct transformation of methane is methanol, one of the most important raw materials in the global industry, which has shown increasing annual demand. Motivated by the current scenario of high availability and immediate search for valorization processes, this proposal presents the development of single-atom noble metal catalysts supported on doped mesoporous cerium dioxide for direct and efficient conversion of methane to methanol under mild reaction conditions. The low activation energies and capacity to stabilize methanol intermediates provided by the single-atom sites associated with high oxygen storage capacity and mobility, characteristic of doped CeO2 supports, can be determinant properties to obtain efficient catalysts for the process. Through the information obtained by the physical and chemical characterization of materials, using ex situ and in situ techniques, the ideal conditions of preparation and the mechanisms involved in the reaction will be determined, to establish the appropriate operating conditions leading to maximum productivity.