Monolithic Catalysts for VOC Oxidation

The dichloromethane, ethyl acetate (EA) and ethanol (EtOH) catalytic activities of as-prepared monolithic catalysts were tested in a conventional fixed-bed reactor, and the monolithic catalysts were placed in the constant temperature zone of the reactor. The reactor was continuously heated and the temperature of the reactor was maintained at the set temperature before analysing the VOCs concentration. The gaseous reactants (DCM, EA and EtOH) were generated by air stream through the liquid reactants in a saturator, and then diluted by another air stream. Here, the indoor air without any purification was used. The liquid reactants were maintained at 0 °C in an ice-water bath during the experiments, respectively. The mass flow controllers (Sevenstar Electronics) were applied to regulate the air intake flow. The total flow was about 6.05 L min⁻¹ and the gas hourly space velocity (GHSV) was kept at 15 000 h⁻¹ with an initial gaseous reactant concentration of about 1000 ppm that was tested at 250 °C in inlet. The DCM concentration in both inlet and outlet of the reactor was monitored by the gas chromatograph (Fuli, China) with flame ionization detector (FID). The schematic diagram of experimental set-up is displayed in Fig. S1.† Additionally, the ethyl acetate and ethanol concentration in both inlet and outlet of reactor was analyzed by the EXPEC 3200 portable gas chromatograph (Hangzhou PuYu Technology Development Co., Ltd. China) with flame ionization detector. The CO₂ was analysed by the GC with a Ni convertor furnace. The DCM conversion (%) and CO₂ yield (%) were calculated by using the following equation:where [DCM]_in denotes the DCM concentration in the inlet gas. [DCM]_out denotes the DCM concentration in the outlet gas.where [CO₂]_in is the CO₂ concentration in the inlet. [CO₂]_out is the CO₂ concentration in the outlet. [DCM]_in is the DCM concentration in the inlet gas.