Bifunctional catalysts composed of low silicon‐content SAPO‐34 nanosheets and In₂O₃/ZrO₂ with improved performance for CO₂ hydrogenation

Abstract

The conversion of CO 2 into high-value chemicals has drawn a great deal of consideration, of which the most ideal product is lower olefins. However, the modified Fischer-Tropsch (F-T) synthesis with CO as an intermediate shows poor selectivity for lower olefins. Here, a list of bifunctional catalysts consisting of SAPO-34 zeolites with adjustable silicon contents and In 2 O 3 /ZrO 2 were synthesized. In the reaction process, CO 2 is first hydrogenated to methanol over an In 2 O 3 /ZrO 2 catalyst, and then the generated methanol rapidly diffuses to the adjacent zeolite catalyst to react to lower olefins. The selectivity of lower olefins (88.3%) and conversion rate of CO 2 (23.3%) was achieved over In 2 O 3 /ZrO 2 and SAPO-34-0.05 at 633 K, a gas hourly space velocity (GHSV) of 4500 ml•gcat -1 •h -1 , and H 2 /CO 2 /Ar = 3:1:1. The catalytic performance remained stable after 50 h of reaction. Characterization analysis showed that Si content affected the content of Brønsted acid sites (BAS) and morphology of SAPO-34, resulting in different distribution of reaction intermediates. Tetramethyl-benzenes, as important

Recent Progress of SAPO-34 Zeolite Membranes for CO2 Separation: A Review

“…Due to these characteristic features, SAPO-34 has been extensively used in the methanol to olefin (MTO) process [ 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 ]. In recent years, SAPO-34 has been investigated for CO 2 remediation, including CO 2 capture [ 49 , 50 , 51 ], conversion [ 52 , 53 , 54 ], and separation [ 49 ]. Several studies have already covered a vast area of SAPO-34 materials research.…”