NO reduction by CO over CuO–CeO2 catalysts: effect of preparation methods

Mesoporous NiO–CeO2 catalysts for CO oxidation: Nickel content effect and mechanism aspect

“…From Fig. 5, it can be found meso-Ni 0.2 Ce displays the most intensive O 2 2− signal, which is in line with the concentration of oxygen vacancy calculated by the area ratio of peaks at 463 and 600 nm (A 600 /A 463 , Table 1) [36], indicating a close relationship of doped nickel ions, oxygen vacancy and activated oxygen species.…”

Small CuO clusters on CeO2 nanospheres as active species for catalytic N2O decomposition

“…Taking into account the results of UV-Vis diffuse reflectance and XRD examinations for this sample (note that no contribution could be observed for the segregated (bulk) CuO phase), the measured reduction peaks can be ascribed to highly dispersed or even atomically dispersed copper species. Accordingly to the literature data, the first reduction peak (␣) corresponds to the reduction of finely dispersed Cu 2+ strongly interacting with the CeO 2 support [25,26]. As it was stressed by Luo et al [27], such kind of Cu species is easily reducible, since strong interaction with CeO 2 enhance CuO reducibility.…”

“…This effect is reported to originate from electronic interactions between the two phases, which weakens the M O bonding and therefore enables reduction under milder conditions. Accordingly to the literature data, we can attribute the detected reduction peaks to the following processes: (i) reduction of finely dispersed Cu 2+ , (ii) partial CeO 2 reduction, (iii) reduction of weak magnetic associates including several Cu 2+ ions, (iv) reduction of small CuO clusters, and (v) reduction of bulk CuO [25][26][27][28][29][30][31].…”

“…As it was stressed by Luo et al [27], such kind of Cu species is easily reducible, since strong interaction with CeO 2 enhance CuO reducibility. The second peak (␤) with a maximum at 116 • C most probably corresponds to a concurrent reduction of ceria [26]. Co-reduction of ceria at such low temperature can be explained by redox equilibria, which take place in CuO/CeO 2 mixed oxides: Ce +4 + Cu +1 ↔ Cu +2 + Ce +3 and Cu 0 + Ce +4 ↔ Ce +3 + Cu +1 [28,29].…”

Effect of Calcination Temperature on NO–CO Decomposition by Pd Catalyst Nanoparticles Supported on Alumina Nanofibers

“…The NO molecules absorb on the surface of the catalysts due to their unpaired electrons [53,54]. Thus, the decline in surface area causes a decline in the NO adsorption and, in turn, reduces the contact between catalyst on the alumina nanofiber and NO-CO molecules [55]. Therefore, the catalytic performances of Pd/amorphous-Al 2 O 3 calcined at 650 • C had better conversion compared to Pd/γ and α-Al 2 O 3 calcined at 750-1150 • C.…”