Shin Hyejin, Vikrant Kumar, Kim Ki-Hyun, Heynderickx Philippe M, Boukhvalov Danil W
Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, Seoul 04763, Republic of Korea.
Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, Seoul 04763, Republic of Korea.
Sci Total Environ. 2024 Mar 10;915:169612. doi: 10.1016/j.scitotenv.2023.169612. Epub 2023 Dec 27.
The thermocatalytic oxidative potential of various supported noble metal catalysts (SNMCs) is well-known for hazardous volatile organic compounds (VOCs), e.g., formaldehyde (FA) and toluene. However, little is known about SNMC performance against ambient VOC pollution with low concentration (subppm levels) relative to industrial effuluents with high concentrations (several hundred ppm). Here, the thermocatalytic oxidation performance of a titanium dioxide (TiO)-supported platinum catalyst (Pt/TiO) has been evaluated for a low-concentration binary mixture of FA and toluene at low temperatures and in the dark. A sample of TiO containing 1 wt% Pt with thermal reduction pre-treatment under hydrogen achieved 100 % conversion of FA (500 ppb) and toluene (100 ppb) at 130 °C and a gas hourly velocity of 59,701 h. Its catalytic activity was lowered by either a decrease in catalyst mass or an increase in VOC concentration, relative humidity, or flow rate. In situ diffuse reflectance infrared Fourier transform spectroscopy, density functional theory simulations, and molecular oxygen (O) temperature-programmed desorption experiments were used to identify possible VOC oxidation pathways, reaction mechanisms, and associated surface phenomena. The present work is expected to offer insights into the utility of metal oxide-supported Pt catalysts for the low-temperature oxidative removal of gaseous VOCs in the dark, primarily for indoor air quality management.
各种负载型贵金属催化剂（SNMCs）对有害挥发性有机化合物（VOCs），如甲醛（FA）和甲苯的热催化氧化潜力是众所周知的。然而，相对于高浓度（几百ppm）的工业废水，SNMCs对低浓度（亚ppm水平）的环境VOC污染的性能却知之甚少。在此，评估了二氧化钛（TiO）负载的铂催化剂（Pt/TiO）在低温和黑暗条件下对FA和甲苯低浓度二元混合物的热催化氧化性能。在氢气气氛下进行热还原预处理的含1 wt% Pt的TiO样品，在130°C和气体 hourly velocity 为59,701 h时，实现了FA（500 ppb）和甲苯（100 ppb）的100%转化。相对于催化剂质量的减少或VOC浓度、相对湿度或流速的增加，其催化活性均降低。采用原位漫反射红外傅里叶变换光谱、密度泛函理论模拟和分子氧（O）程序升温脱附实验来确定可能的VOC氧化途径、反应机理及相关表面现象。本工作有望为金属氧化物负载的Pt催化剂在黑暗中低温氧化去除气态VOCs的应用提供见解，主要用于室内空气质量管理。
