Bench scale study of electrochemically promoted CO2 capture on Pt/K-βAl2O3

Due to the continuous increase in CO2 atmospheric levels resulting from fossil fuels combustion, it is necessary to develop new, more efficient and less-energy intensive processes, that allow economically and selectively separate CO2 without the negative impact of co-existing gases (H2O, SO2, NO, etc.). Electrochemically promoted CO2 capture shows potential to fulfil this challenge. This work presents a bench-scale study of the electropromoted CO2 capture over Pt on K-beta Al2O3, at high flow rate and using simplified exhaust gas compositions (CO2/N-2 and CO2/O-2/N-2) and easily scalable catalyst-electrode configurations. Three Pt catalyst films were prepared by different procedures. On the basis of previous mechanistic and spectroscopic studies, cyclic voltammetry and electropromoted CO2 capture studies showed that the system is able to capture CO2, not only by electropromoted adsorption but also as carbonates by potassium ions electrochemically supplied to Pt surface. CO2 capture is enhanced on decreasing Pt particle size and in the presence of O-2. Temperature improves also CO2 capture within the stability window of the formed species. The Pt/K-beta Al2O3 system can be regenerated, allowing CO2 separation, by electrochemical decomposition of previously stored compounds without increasing temperature. (C) 2013 Elsevier Ltd. All rights reserved.