Production of Isobutylene from Syngas – Isosynthesis Over Zirconia-Based Catalysts

作者：Niko Heikkinen, L. Keskiväli, Krista Kuutti, Rasmus Ikonen, Bhumi A. Baraiya, Ville Korpelin, Manu Lahtinen, J. Kanervo, Mikko J. Heikkilä, Xinwei Ye, B. Weckhuysen, K. Honkala, Juha Lehtonen, M. Reinikainen · 发表于：Topics in catalysis · 年份：2025 · DOI：10.1007/s11244-025-02184-y · 被引用次数：4

This study presents the conversion of syngas (synthesis gas, CO + H2) into isobutylene with monoclinic zirconia (m-ZrO2), mixed monoclinic/tetragonal zirconia (m/t-ZrO2), tetragonal zirconia (t-ZrO2) and Ce/La-doped zirconia samples. The physical and chemical properties of the catalyst samples were characterised with nitrogen physisorption, NH3 and CO2 temperature-programmed desorption (TPD) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Sample material crystal structures were analysed with powder X-ray diffraction (PXRD) analysis. The pure monoclinic ZrO2 sample showed the best catalytic performance with 66% CO conversion and 44 mol-% C/hydrocarbons isobutylene selectivity at reaction conditions of 450 °C, 45 bar, GHSV = 2000 h−1, and CO: H2 = 1:1. While pure monoclinic ZrO2 was a highly efficient catalyst for the isosynthesis reaction, pure tetragonal ZrO2 produced only a minor amount of isobutylene (~ 1 mol-%C/hydrocarbons). Interestingly, Ce/La-doped zirconia had a cubic/tetragonal crystal structure, while showing selectivity and activity comparable to m-ZrO2 (CO conversion 64% and isobutylene selectivity of 40 mol-% C/hydrocarbons). Although samples with a purely t-ZrO₂ crystal phase significantly reduced the desired isobutylene selectivity, catalysts with relatively high Ce/La loadings (17% and 5% of the total catalyst mass) in the cubic/tetragonal crystal structure achieved high isobutylene activity and selectivity, owing to the dopant-induce...