MnO x ‐loaded Mesoporous Silica for the Catalytic Oxidation of Formaldehyde. Effect of the Melt Infiltration Conditions on the Activity – Stability Behavior

Conventional melt infiltration (over calcined SBA‐15 silica support) and optimized melt infiltration (over surfactant‐containing SBA‐15 support) were used for the first time to prepare MnO x nanoparticles encapsulated within the support pores. A comprehensive study on the evolution of textural, structural, and morphological characteristics of the MnO x ‐silica composites as well as their redox and surface properties is reported herein by varying synthesis parameters, such as manganese loading (5, 10, 20 and 30 Mn wt.%), and post‐treatment temperature (300 and 500 °C). The catalytic performances of the materials prepared in this work have been evaluated in the catalytic oxidation of formaldehyde. The results show a high performance of the SBA‐15 supported manganese oxide at low‐ to moderate‐ temperatures of reaction (Temperature at 50 % of HCHO conversion into CO 2 ranging from 110° to 150 °C), activity being related to Mn oxidation state (from 2.3 to 4) and MnO x phase location, confined with or without 2D spatial distribution in the support porosity or formed at the external surface of SBA‐15. A high stability (60 hours), under dry air and 50 % relative humidity air, is reported for MnO x ‐based nanocatalysts prepared by conventional and optimized melt infiltration procedures.