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Seeking highly dispersed noble metals catalysts with varied valence, together with oxygen species and Lewis acid regulation are an important way to meet high efficiency toluene oxidation. Herein, the catalyst of 1 wt.% Pt and 1 wt.% Pd loaded on Al2O3 modified with La, Ce (PtPd/LCA), is synthesized through the adjustment of different calcination temperature from 250 to 550 °C under ascorbic acid reduction. Their redox, surface oxygen species, surface species acid properties and reaction mechanism were systematically characterized by H2-TPR, O2-TPD, XPS, pyridine-IR and in-situ DRIFTS. PtPd/LCA-250 totally eliminats toluene at 175 °C under 60,000 mL−1 g−1 h−1, together with superior water resistance and stable performance. Lower calcinated temperature and reduction of ascorbic acid, which leading to the proper co-existence of Pd and PdO, together with the abundant surface chemically adsorbed oxygen species and Lewis acid sites, is responsible for better catalytic activity. The catalyst could be a step forward in designing efficient and facile technologies for abatement of VOCs. [ABSTRACT FROM AUTHOR]

A bifunctional adsorption-catalysis system for the abatement of trace amounts of toluene was developed and realized by loading different amounts of Pt on mesoporous silica synthesized with ionic liquid with hydrophobic modification. The textural properties were evaluated using BET, contact angle, XRD, IR, XPS, TEM, and H2-TPR techniques. The capability of the synthesized catalysts for room-temperature adsorption and low-temperature catalysis of toluene was appraised. The hydrophobic sample exhibited better toluene adsorption capacity of 53.1 mg g−1 than SiO2-350 and 3.0Pt/SiO2 samples with 28.3 mg g−1 and 18.9 mg g−1, respectively. Furthermore, the hydrophobic sample showed increased maximum desorption temperatures of 52 °C in comparison with those at 44 °C and 37 °C, which acted as a good adsorption buffering system. 3.0Pt/SiO2-H showed the best toluene conversion capacity at T90 = 129 °C, together with superior water vapor resistance and sequential capture-destruction performances. The increased bifunctional adsorption-catalysis performance with hydrophobic modification may be ascribed to the change in surface functional groups. The prepared system could be a valuable candidate material for adsorption-catalysis integration and assistance for VOCs elimination technology in barren waste gases. [ABSTRACT FROM AUTHOR]

[Display omitted] • CuMn 2 O 4 /Mn 2 O 3 heterojunctioned photothermal catalyst was prepared by a facile sol–gel method with a calcinating process. • CuMn 2 O 4 /Mn 2 O 3 photothermal catalyst exhibited excellent full spectrum light absorption capacity, photo-thermal conversion ability and toluene conversion performance with a 90% toluene conversion (T = 233 °C, WHSV = 30,000 mL/g·h), together with a good catalytic stability. • The excellent photothermal catalytic performance was attributed to the synergistic effect of abundant oxygen vacancies, Mn3+ active sites and heterojunctions between CuMn 2 O 4 and Mn 2 O 3. Photothermal catalyst oxidation of VOCs is a hot issue in the air purifier field due to the reducing of secondary energy consumption. Herein, we reported a photothermal catalyst CuMn 2 O 4 /Mn 2 O 3 with heterojunction for catalytic oxidizing toluene with high efficiency through sol–gel method followed different calcination temperature. Under the irradiation of 700 mW/cm2 Xe lamp simulated sun light, the CuMn 2 O 4 /Mn 2 O 3 catalyst exhibited excellent full spectrum light absorption capacity, photo-thermal conversion ability and toluene conversion performance with a 90% toluene conversion (T = 233 °C, WHSV = 30,000 mL/g·h), together with a good catalytic stability. The excellent performance can be attributed to the synergistic effect of abundant oxygen vacancies, Mn3+ active sites and heterojunctions between CuMn 2 O 4 and Mn 2 O 3 due to the XPS, H 2 -TPR, UPS characterizations. [ABSTRACT FROM AUTHOR]