La-Based Perovskites Combined with HZSM-5 for Selective Conversion of Syngas into Aromatics

摘要

Improving catalytic selectivity with high conversion meets big challenge for direct conversion of syngas (CO/H-2) to aromatics (STA). Here, a series of LaBO3 (B=Fe, Co, Ni, Mn, Cr) perovskite oxides was synthesized and applied as metal oxide component of OX-ZEO bifunctional catalysts for STA firstly. By combining with HZSM-5, LaFeO3, LaMnO3 and LaCrO3 exhibited good performance on syngas conversion. For the bifunctional catalyst of LaFeO3/HZSM-5, a superior catalytic performance with 82.0 selectivity to aromatics at 28.5 CO conversion was achieved. The composition of B-site metals in perovskites and its stabilization in the structure are essential for activity of STA reaction. In situ DRIFTs study revealed the syngas conversion over perovskite followed the surface formate and methoxy intermediate species transformation pathway.