Morphology-dependent oxygen vacancies and synergistic effects of Ni/CeO₂ catalysts for N₂O decomposition

Abstract

Strong morphology-dependent oxygen vacancies and synergistic effects of Ni/CeO2 catalysts and their vital effects on N2O decomposition.

High Channel Density Ceramic Microchannel Reactor for Syngas Production

“…There was no NiAl 2 O 4 spinel formed, as indicated by the absence of high temperature process above 800 • C and the XRD results. In comparison, the Ni/CGO/MCR sample was reduced at lower temperature as a result of a synergic effect with CGO, acting as an excellent oxygen conductor [37]. This process corresponds to the reduction of bulk NiO to Ni, as well as the reduction of surface Ce 4+ to Ce 3+ capping CGO [37].…”

“…In comparison, the Ni/CGO/MCR sample was reduced at lower temperature as a result of a synergic effect with CGO, acting as an excellent oxygen conductor [37]. This process corresponds to the reduction of bulk NiO to Ni, as well as the reduction of surface Ce 4+ to Ce 3+ capping CGO [37]. The reduction happens, however, in two close steps: one at 290 • C and a second one at 320 • C. This may be due to the different interactions between Ni and the support.…”

“…This strong affinity between the surface oxygen vacancy of CGO and the interface terminal oxygen ion of NiO causes the Ni=O bond to be weakened. In that case, surface oxygen can oxidize hydrogen at low temperatures [37,38].…”

NaBH4 Surface Modification on CeO2 Nanorods Supported Transition‐Metal Catalysts for Low Temperature CO Oxidation

“…According to Luo et al, [42] the peak γ is corresponding to the reduction of bulk CuO. [56] For 10NiO x À mCeO 2 NR catalyst, according to the literatures, [33,57,58] the peak at 190°C attributes to the surface active adsorbed oxygen species (i. e. in Ni-OÀ Ce) and the peak at 277°C is corresponding to the reduction from highly dispersed NiO species to Ni. For 10CoO x À mCeO 2 NR catalyst, the first intense reduction peak at 196°C is assigned to the reduction of Co 3 O 4 phase to CoO and the second peak at 293°C is due to the reduction of CoO to metallic Co. [59,60] The broad peak around 473°C is due to the surface reduction of CeO 2 NR support.…”

Hydrothermal microwave‐assisted synthesis of LaFeO3 catalyst for N2O decomposition

“…All the noble metal based systems are supported catalysts, and the nature of the interactions of a noble metal with the support plays also a crucial role in their activity. [27][28][29] The main disadvantage of noble-metal catalysts is the high cost, so chemists are mostly looking for suitable catalytic materials from the second groupnon-noble-metal oxide catalytic systems 22 which include a wide range of oxide types such as bulk oxides, [30][31][32] spinels, 33,34 perovskites, hexaferrites, hydrotalcites [35][36][37][38][39][40][41] etc. The use of a support allows one to increase the specific activity of metal particles due to the enhanced dispersity, which is convincingly illustrated by examples of Fe 2 O 3 and Co 3 O 4 supported on ZrO 2 catalysts.…”