Low‐Temperature CO Oxidation over a Ternary Oxide Catalyst with High Resistance to Hydrocarbon Inhibition

Abstract

Platinum group metal (PGM) catalysts are the current standardf or control of pollutants in automotive exhaust streams.A side from their high cost, PGM catalysts struggle with CO oxidation at lowtemperatures (< 200 8 8C) due to inhibition by hydrocarbons in exhaust streams.H ere we present at ernary mixed oxide catalyst composed of copper oxide,cobalt oxide,and ceria (dubbed CCC) that outperforms synthesized and commercial PGM catalysts for CO oxidation in simulated exhaust streams while showing no signs of inhibition by propene.D iffuse reflectance IR (DRIFTS) and light-off data both indicate lowi nteraction between propene and the CO oxidation active site on this catalyst, and as eparation of adsorption sites is proposed as the cause of this inhibition resistance.This catalyst shows great potential as alow-cost component for low temperature exhaust streams that are expected to be acharacteristic of future automotive systems.

The Effect of Pt Particle Size on the Oxidation of CO, C3H6, and NO Over Pt/Al2O3 for Diesel Exhaust Aftertreatment

“…Even though a typical diesel exhaust contains a variety of 173 hydrocarbon components, propene (C3H6) was used as a model compound for hydrocarbon oxidation, 174 following common practice [5,10,11,23,24,46]. The propene conversion was determined based on the CO2 175 concentrations measured in the product gas, using the same analyzer as for CO oxidation, and the 176 stoichiometry of the reaction equation, forming three CO2 molecules per C3H6 molecule.…”

Nanostructured cerium oxide: preparation, characterization, and application in energy and environmental catalysis

“…Fortunately, recent studies reveal that the physical and chemical properties of ceria can be promoted by introducing foreign component to construct doping structure or solid solution. Until now, many components such as Zn, [73,74] Cu, [75][76][77][78][79][80] Co, [81][82][83] Mn, [84][85][86][87] and Sn [88][89][90] have been applied to dope ceria, which enhance the catalytic CO oxidation performance significantly. With the doping effect, the OSC of ceria can be improved by increasing the number of oxygen vacancies due to the low valence states of doped metal ions, which will greatly enhance the oxygen mobility and low-temperature reducibility, in turn, lead to much better catalytic performances.…”

“…Besides ceria-supported noble metals catalyst, ceria-based composite materials are also widely applied in catalytic total oxidation of hydrocarbons. Among them, the composite oxides such as Mn-Ce-O, [96][97][98][99][100][101] Cu-Ce-O, [102][103][104][105] and Co-Ce-O [83,106] show good activities, where the strong synergistic effect can be promoted by their lattice contact or doping function.…”

Mesoporous Co‐Al oxide nanosheets as highly efficient catalysts for CO oxidation

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Up to now, many highly efficient catalysts for CO oxidation, mainly including supported noble metals (such as Au and Pt) 8,9,11,12,[19][20][21][22][23][24][25] and metal-oxides (such as Co 3 O 4 and MnO 2 ) have been successfully developed. 7,[13][14][15][16][17][18][26][27][28][29][30][31][32][33] For example, TiO 2 -supported Au catalyst is very active for CO oxidation at the temperature of −70 C. 19-21 SiO 2 -supported Pt-Fe catalysts give almost 100% CO conversion and 100% CO selectivity at room temperature. 8 Metal oxides are less expensive compared with supported noble metals, which enhances their potential for practical applications.…”

“…performances in low-temperature CO oxidation and catalytic oxidation reactions. 7,13,[26][27][28][29][30][31][32][33][34][35] Among these materials, cobalt oxide catalysts show excellent performance, and the catalytic activities can be improved through various strategies. For example, Co 3 O 4 nanorods with higher exposure of (110) planes exhibit full conversion of CO at −77 C. 7 35 After the introduction of mesoporosity, the mesoporous Co 3 O 4 catalyst with enhanced surface area becomes more active than the bulk one, giving T 50 (temperature for 50% CO conversion) value of 4 C. 34 Upon doping In 3+ species into Co 3 O 4 , the catalyst can completely convert CO to CO 2 at temperatures as low as −105 C. 26 Clearly, the strategies for exposure of catalytically active sites such as inducing of mesoporosity is highly efficient.…”