Ni-Zn impregnated on hierarchical ZSM-5 from natural minerals as catalyst for carboxylation reaction of ethyne with CO2

Abstract

Carbon dioxide is one of the main gases that cause greenhouse gas emissions in the atmosphere. One way to reduce gas emissions is to convert CO2 and produce high-value products. Because it is atmospherically inert, catalyst assists CO2 to react with other compounds. In this research, hierarchical ZSM-5 was prepared from natural minerals as sources, which is Bayat zeolite and Bangka kaolin, then impregnated with bimetal Ni-Zn as a catalyst to convert CO2 in the presence of ethyne to produce acrylic acid. Natural mineral-based hierarchical ZSM-5 was prepared using double template method, with TPAOH as a primary template that directed to MFI framework and PDDA-M as a secondary template that directed mesoporous structure. Impregnation of nickel (Ni) and zinc (Zn) bimetallic was conducted by co-impregnation method followed by reduction with H2 gas flow. Material characterization such as FTIR, XRD, XRF, SAA, and SEM-EDX were conducted on the catalyst. FTIR analysis shows that there has been a complete decomposition of templates through calcination. XRD analysis shows the crystallinity of the hierarchical ZSM-5 natural which indicates the synthesis was successful. SEM analysis shows the morphology of the material with the coffin like-shaped which is characteristic of the ZSM-5. The EDS analysis shows percent loading of Ni and Zn in ZSM-5 respectively is 6.38 % and 3.23 %. The ethyne carboxylation reaction with CO2 was carried out in a batch reactor with pressure variations of 1.5 bar, 2.5 bar, and 3.5 bar. The products formed were analyzed by HPLC.