Limitations of proton-conducting materials as supports for Pt-catalyzed ethane dehydrogenation in membrane reactors
Year: 2025
Type: article
Abstract: Olefin formation via non-oxidative dehydrogenation of light alkanes is limited by thermodynamic equilibrium. A possible strategy to increase olefin yields aims at removing H2 from the reaction zone using proton-conducting membranes. An attractive proposition is to deposit the catalyst directly onto the proton-conducting material to optimize hydrogen transport. To test this concept a Pt dehydrogenation catalyst was deposited onto lanthanum tungstate (LWO) and barium zirconium cerium yttrium (BZCY) oxides, which are prototypical materials in proton-conducting ceramics. The performance of Pt/LWO and Pt/BZCY was compared to a conventional Pt/ZnAl2O4 dehydrogenation catalyst in the non-oxidative dehydrogenation of ethane. The ethylene selectivity on Pt/LWO and Pt/BZCY was much lower than for Pt/ZnAl2O4, at the cost of a higher methane selectivity. Methane formation is possibly boosted by C-C cleavage on Lewis acid sites of the LWO and BZCY supports. These acid sites originate from the presence of oxygen vacancies in LWO and BZCY. Additionally, Pt/LWO deactivated rapidly in dry atmospheres, due to Pt sintering. This sintering, however, was suppressed when cofeeding steam. The presence of steam, unfortunately, led to the formation of Brønsted acid sites in Pt/LWO that further decreased ethylene selectivity. The Pt/BZCY system was comparably stable relative to Pt/LWO, which was attributed to relatively strong interactions between Pt and the Ba in the support. Implementing these materials as catalyst supports requires significant improvements to compete with the conventional Pt/ZnAl2O4 catalyst. Addressing this issue will be key to enable large-scale implementation of proton ceramic catalytic membrane reactors for alkane dehydrogenation.
Source: Applied Catalysis A General
Authors: Jord P. Haven, Leon Lefferts, Jimmy A. Faria Albanese
Institution: University of Twente
Language: English
Subfield: Catalysis
Field: Chemical Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,760
OpenAlex ID: W7115081072