Systematic Catalyst Screening of Zeolites with Various Frameworks and Si/Al Ratios to Identify Optimum Acid Strength in OME Synthesis
Anja Fink, Christian Henning Gierlich, Irina Delidovich, Regina Palkovits
Abstract
Abstract Oxymethylene dimethyl ethers (OME x oligomers with the chain length x) present a promising emission reducing diesel additive, which can potentially be produced based on renewable resources. In this work, the OME x synthesis catalysed by zeolites was investigated starting from paraformaldehyde and methanol. The catalytic performance of zeolites with different framework types (BEA, FAU, MFI, MOR) and various Si/Al ratios was comparatively studied. The zeolites were characterised by means of NH 3 ‐TPD, ICP‐OES, XRD and N 2 physisorption. A relationship between catalytic activity and Si/Al ratio was established demonstrating the highest turnover frequency for zeolites with high Si/Al ratios. HZSM‐5 114 with a TOF of 3375 mol OME3–5 mol AcidSites −1 h −1 was determined as the best‐performing zeolite which indicates that the OME x synthesis requires a moderately strong acid strength.