Center for Excellence in Regional Atmospheric Environment, Key Laboratory of Urban Pollutant Conversion, Xiamen Key Laboratory of Materials for Gaseous Pollutant Control, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Environ Sci Technol. 2023 Jan 17;57(2):1123-1133. doi: 10.1021/acs.est.2c06514. Epub 2022 Dec 13.
The miscellaneous volatile organic compounds (VOCs) in industrial flue gas streams usually demonstrate significant mutual inhibition effects, and the behavior of a particular VOC in mixtures is not clear, which hinders the application of catalytic technology. This study examines the catalytic oxidation and mixing effects of representative VOCs in industrial exhausts, consisting of acetone (AC), ethyl acetate (EA), and toluene (Tol), on common Mn-based catalysts (e.g., MnO, MnO, LaMnO, and MnO) by means of intrinsic activity evaluation, coadsorption, VOC temperature-programmed oxidation, in situ diffuse reflectance infrared Fourier transform spectroscopy, and gas chromatography-mass spectrometry. The results showed no inhibiting effect on the conversion of these VOCs when combusted together; instead, a significant mutual promotion effect was found, especially on Tol destruction, with a sharp decrease in the Tol from 214 to 158 °C on MnO. It is proposed for the first time that the addition of AC/EA in Tol combustion leads to the generation of /-methyl phenol, which changes the rate-determining step of the ring-opening process, thus elevating the conversion of Tol together with AC and EA in the mixture at low temperatures.
工业烟道气中的杂项挥发性有机化合物（VOCs）通常表现出显著的相互抑制效应，混合物中特定 VOC 的行为不明确，这阻碍了催化技术的应用。本研究通过本征活性评价、共吸附、VOC 程序升温氧化、原位漫反射红外傅里叶变换光谱和气相色谱-质谱联用等手段，考察了工业废气中代表性 VOC（如丙酮（AC）、乙酸乙酯（EA）和甲苯（Tol））在常见的 Mn 基催化剂（如 MnO、MnO、LaMnO 和 MnO）上的催化氧化和混合效应。结果表明，这些 VOC 一起燃烧时没有转化抑制作用，反而发现了明显的相互促进作用，特别是在 Tol 破坏方面，MnO 上 Tol 的从 214 降至 158°C。首次提出在 Tol 燃烧中添加 AC/EA 会生成 /-甲基苯酚，从而改变开环过程的速控步骤，从而在低温下提高混合物中 Tol 与 AC 和 EA 的转化率。
