Electrochemical promotion of CO2 hydrogenation in a monolithic electrochemically promoted reactor (MEPR)

The electrochemical promotion of the CO2 hydrogenation was investigated, using a monolithic electropromoted reactor (MEPR) loaded with nine, connected in parallel, Ru/YSZ/Au electrochemical cells. The study was carried out at ambient pressure and in the temperature range between 220 degrees C and 370 degrees C, using high reactant flowrates (up to 2500 cm(3)/min) and reducing conditions (P-CO2/P-H2 =1/7). For an intermediate flowrate of 1000 cm(3)/min, the selectivity to methane (S-CH4) was 100 % for temperatures up to 300 degrees C. Further increase in temperature resulted to a decrease in selectivity to methane with a concomitant increase of the corresponding yield (Y-CH4) due to the higher CO2 conversion. However, the total performance of the reactor, in terms of methane selectivity and yield, was affected significantly under electropromoted conditions. At the maximum studied temperature of 370 degrees C, the unpromoted values of S-CH4 and Y-C(H4) were 84 % and 24 % respectively, while O2- supply to the catalytic surface enhanced theses values to 92 % and 32 % respectively. The qualitative features of electropromotion, i.e. electrophobic behavior for methanation and electrophilic behavior for the RWGS reaction, were in agreement with previous EPOC studies of CO2 hydrogenation in laboratory scale reactors showing a successful scale up of Electrochemical Promotion of Catalysis (EPOC). In addition, the good performance of the monolithic reactor under severe operating conditions of high flowrates and temperatures is a promising result for further scale-up and for the practical utilization of EPOC.

Automated summary

The study investigated the electrochemical promotion of CO2 hydrogenation using a monolithic electropromoted reactor with nine electrochemical cells. The results showed that under high reactant flowrates and temperatures, the electropromotion significantly affected the methane selectivity and yield. The experimental results on the monolithic reactor successfully scaled up the laboratory-scale EPOC studies of CO2 hydrogenation.