Electrochemical Activation of Ni Catalysts with Potassium Ionic Conductors for CO2 Hydrogenation

• Published in: Topics in catalysis Vol. 58; no. 18-20; pp. 1256 - 1269
• Main Authors: Gutiérrez-Guerra, N., González-Cobos, J., Serrano-Ruiz, J. C., Valverde, J. L., de Lucas-Consuegra, A.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.11.2015
• Subjects: Catalysis; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Industrial Chemistry/Chemical Engineering; Original Paper; Pharmacy; Physical Chemistry; Methanation; Ni catalyst; Reverse water gas shift; Syn-gas; removal; CO; EPOC
• ISSN: 1022-5528; 1572-9028
• DOI: 10.1007/s11244-015-0488-4

Three different kind of Ni-based catalysts were prepared on a K-β″Al 2 O 3 solid electrolyte by combining the annealing of an organometallic paste and the addition of a catalyst powder. The different catalysts films were tested in the CO 2 hydrogenation reaction under electrochemical promotion by K + ions, and were characterized by XRD and SEM. The catalyst film derived from the addition of an α-Al 2 O 3 powder to the Ni catalyst ink presented the highest catalytic activity as a result of the increase in Ni catalyst film porosity. The influence of the applied potential and other operation variables were evaluated on the Ni catalytic activity and selectivity. Hence, the CO production rate was enhanced either by decreasing the applied potential (with the consequent supply of K + ions to the catalyst surface) or by increasing the CO 2 (electron acceptor) feed concentration. On the other hand, CH 4 production rate was favoured at positive potentials (removing K + from the catalyst surface) or by increasing the H 2 (electron donor) feed concentration. The global CO 2 consumption rate increased upon negative polarization in all experiments and the electrochemical promotion of catalysis effect showed to be reversible and reproducible. Hence, the electrochemical promotion phenomena demonstrated to be a very useful technique to in situ modify and control the catalytic activity and selectivity of a non-noble metal such as Ni for the production of CH 4 or syngas via CO 2 valorization.