PtPd/molecular sieve as dual-functional monolithic adsorbent/catalyst for effective removal of trace toluene at low-temperature and their electric-heating performance

A dual-functional adsorption-catalytic system for elimination of trace toluene is developed and realized over molecular sieve-hosted varied ratio of platinum and palladium catalysts. PtPd/molecular sieve exhibites PdO and PtO2 around 2-3 nm particles with uniform loading verified by XRD, TEM, Raman and XPS. The adsorption-desorption-catalysis for trace toluene purification is evaluated on the quartz micro-reactor and the self-made electrically heated equipment. 3Pt1Pd/molecular sieve shows toluene adsorption capacity of 18.22 mg/g and desorption efficiency about 77%, together with the maximum des-orption temperature at 100 degrees C. 3Pt1Pd/molecular sieve owns toluene conversion with 38.3% and 100% at 100 and 200 degrees C, accompanied with the higher CO2 selectivity of 0.0% and 150.0%, separately, due to the higher Pd(2+)content. The catalyst displays water vapor endurance, reproducibility, and 83.0% carbon bal-ance during the whole adsorption-desorption-catalysis within 150 min, which highlights the sustainable applicability in lean VOCs abatement. Furthermore, the possible catalytic reaction pathway of toluene oxidation is proposed based on the in-situ DRIFTS experiments. (C) 2022 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved