Electrochemical promotion and characterization of PdZn alloy catalysts with K and Na ionic conductors for pure gaseous CO2 hydrogenation. (December 2016)

• Record Type: Journal Article
• Authors: Díez-Ramírez, J.; Sánchez, P.; Valverde, J.L.; Dorado, F.
• Is Part Of: Journal of CO₂ utilization. Volume 16(2016)
• Page Start: 375
• Page End: 383
• Publication Date: 2016-12
• Subjects: Electrochemical promotion of catalysis (EPOC) -- CO2 hydrogenation -- PdZn alloy -- Methanol production; Carbon dioxide -- Periodicals; Carbon dioxide -- Environmental aspects -- Periodicals; Carbon dioxide mitigation -- Periodicals; Carbon dioxide; Carbon dioxide -- Environmental aspects; Carbon dioxide mitigation; Periodicals; 628.53205
• DOI: 10.1016/j.jcou.2016.09.007
• Languages: English
• ISSNs: 2212-9820

Abstract

Graphical abstract: Highlights: PdZn alloy was used for the first time as a catalytic electrochemical film. The PdZn alloy proved to be active for CO2 hydrogenation to give CO and CH3 OH. The EPOC effect varies depending on the particles (metallic Pd or PdZn alloy). The apparent Faradaic efficiency for CO reached values higher than 1000. Abstract: A PdZn alloy has been used for the first time as a catalytic electrochemical film for CO2 hydrogenation. Three different electrochemical systems were prepared to study the influence of the Pd/Zn ratio and the presence of potassium and sodium ions. These catalysts were characterized by XRD, SEM and cyclic voltammetry and then tested in the hydrogenation of CO2 at three different H2 /CO2 feed ratios (3, 9 and 39) and three temperatures (300, 320 and 340 °C) with electrochemical promotion by Na + and K + ions. CH3 OH and CO were the only two products detected. During the electrochemical promotion, a low quantity of ions increases the formation rate of CH3 OH and a high quantity leads to the poisoning of the PdZn active sites. The catalysts which have palladium and the palladium-zinc alloy in their structure show an electrophilic behavior in the CO formation and when only the alloy is formed in the catalyst, the CO has the same behavior found for the methanol. Apparent Faradaic efficiency values above 1000 were obtained under the different conditions tested.