Room-Temperature Complete Oxidation of Formaldehyde over Lactic Acid-Modified HZSM-5-Supported Pt Catalyst

Room-temperature complete oxidation of formaldehyde (HCHO) is an important orientation of research programs, yet challenges remain. The development of efficient catalysts with high activity and excellent stability is of great significance for such practical application. Inspired by this whole catalytic process, we, therefore, chose HZSM-5 zeolite with abundant acidic sites as catalyst support and lactic acid (LA) as modifier to regulate the properties. The use of LA simultaneously enhances the hydroxyls density and increases the dispersion of Pt nanoparticles, which are better than the reference catalyst prepared via direct wetness impregnation method. Most satisfying of all, the lactic acid-modified HZSM-5-supported Pt catalyst demonstrates a remarkable reaction performance for room-temperature HCHO oxidation at a high concentration HCHO of 80 ppm and a large space velocity of 360,000 mL/g/h (especially with a low Pt loading of 0.5%). In addition, a 120 h test further confirms the favorable stability of the designed catalyst. This pre-modified strategy using organic acid might provide potential approach in the construction of efficient zeolite-supported catalysts.