Effect of the surface composition of MnOX-CeOX 3D-printed monolithic catalysts toward total oxidation of toluene.

Successful fabrication of Mn-based 3D-printed monoliths by stereolithography (SLA) is reported for the first-time in this work. The catalytic performances, as function of the surface composition, of the developed monoliths were evaluated by the total oxidation of toluene. The monolith with a surface composition of Mn0.7Ce0.3 showed the highest catalytic efficiency (98%) with a T90 value of 322 °C and acceptable catalytic stability after a second reaction cycle. By changing space velocity values, the T90 value can decrease to 311 °C. Microstructural and surface characterizations confirm the formation of Mn2O3 and Ce species on Mn sites and the homogeneous dispersion of Mn and Ce species on the surface of the 3D-printed monoliths. For comparison purposes, a single MnOX and CeOX monoliths were also synthesized and tested by toluene total oxidation, which confirms the cooperative effect between the oxygen storage capacity of Ce and the redox ability of Mn species observed in Mn0.7Ce0.3 monolith catalyst, giving rise to the highest catalytic activity. These results pointed out the promising catalytic properties of the developed Mn-based 3D-printed monolith catalysts for the total oxidation of volatile organic compounds at a low cost, which is an interesting alternative to mitigating atmospheric emissions.