Preferential oxidation of CO (CO-PROX) over CuOx/CeO2 coated microchannel reactor

Abstract

The general aspects of the synthesis and characterization results of a CuO x /CeO 2 catalyst were presented. In addition the principal steps for manufacturing a microchannel reactor and for the coating of the CuO x /CeO 2 catalyst onto the microchannels walls, were also summarized. The catalytic activity of this microchannel reactor during the preferential oxidation of CO (CO-PROX) was evaluated employing a feed-stream that simulates a reformate off-gas after the WGS unit. Two activation atmospheres were studied (H 2 /N 2 and O 2 /N 2 ). The reducing pretreatment improved the resistance to deactivation by formation of carbonaceous species over the catalyst surface at high temperatures. The presence of H 2 O and CO 2 in the feed-stream was also analyzed indicating that the adsorption of CO 2 inhibited the conversion of CO at lower temperatures because these compounds modified the active sites through the formation of carbonaceous species on the catalyst surface. Finally, the experimental results of the microreactor performance were compared with CFD simulations that were carried out using a kinetic for the CuO x /CeO 2 powder catalyst. The experimental results were reasonably well described by the model, thus confirming its validity.

Au/CeO2 Catalysts: Structure and CO Oxidation Activity

“…However, non-reducible materials with electron-rich oxygen vacancies may also enhance the catalytic activity of gold by activating gaseous oxygen [16,21]. Ceria, due to its chemical properties, has become one of the most promising supports for oxidation reactions and has been broadly studied [7][8][9][10]15,17,20,26,28,51,57,129,143,[159][160][161]. The relevance of cerium oxide, as a support for gold nanoparticles, is mainly based on its high oxygen storage capacity resulting from oxygen mobility in its lattice [47].…”

“…Extensive research carried in our laboratory show the positive effect of a number of dopants including Eu [20,57], Zn [15,17,51], Fe [51,53,174], Cu [37,160], Zr [11,51,179,180], Gd [56], Ni [143], Cr [143], and Co [14], which potentiate ceria defect chemistry resulting in highly effective catalysts for oxidation reactions. Several situations may be envisaged as a function of the dopant cation.…”

Microreactors technology for hydrogen purification: Effect of the catalytic layer thickness on CuO /CeO2-coated microchannel reactors for the PROX reaction

“…2, respectively. F in and F out refer to molar flow rates at the reactor inlet and outlet, respectively [4,20].…”

“…In the case of microreactors, the same reaction set-up was used; however the cylindrical reactor was replaced by two stainless steel cases connecting the inlet and outlet positions of the microchannels, and allowing the contact between the coated walls of the channels and the feed-stream according to that described in [4,20]. The temperature was continuously monitored by 4 K-type thermocouples.…”

“…The manufacturing process of our microreactor prototype coated with 300 mg of catalyst [4,[18][19][20] is summarized in Figure 1. In the present work, this microreactor is named as MR300 and will be compared with a new block coated with 150 mg of catalyst, denoted as MR150.…”