Production of Synthesis Gas from Methane Using Lattice Oxygen of NiO−Cr₂O₃−MgO Complex Oxide

Abstract

To produce nitrogen-free synthesis gas or hydrogen by the partial oxidation of methane using air as an oxidant, NiO-Cr 2 O 3 -MgO complex oxide was proposed as an effective one. Lattice oxygen of NiO in the complex oxide was effectively transferred to CH 4 to give H 2 and CO in the ratio of 2-3:1 at 700 °C. NiO was reduced to metallic Ni during the course of the reaction with CH 4 , and the reduced Ni was successfully oxidized to NiO with air at 700 °C. Repeated cycles of the reaction and oxidation were carried out without any loss of activity. The role of Cr 2 O 3 seemed to weaken the Ni-O bond in NiO-MgO complex oxide, in which NiO is less reducible with CH 4 at 700 °C. In addition, the surface oxidation state of Ni was increased to Ni 3+ with Cr 2 O 3 .

Three-dimensionally ordered macroporous spinel-type MCr2O4 (M = Co, Ni, Zn, Mn) catalysts with highly enhanced catalytic performance for soot combustion

“…As shown in Table 1, the 3DOM catalysts exhibited higher surface area than their bulk counterparts, which could be attributed to the fact that using PMMA as the pore-making template could inhibit the crystal growth during the calcination process and increase the surface area of catalysts. 36 Figure 4B presented two different desorption peaks. It could be seen that the nature of metal atom M has a great influence on the reduction profiles.…”

NO reduction by methane over iron oxides: Characteristics and mechanisms

“…Fe. [25][26][27]31]. Wang and Wei [28] suggested that Fe 2 O 3 could completely oxidize methane to CO 2 below 570°C, while it could partially oxidize methane above 570°C.…”

“…Fe 2 O 3 was used to improve reburning efficiency by reducing HCN to N 2 while Fe 2 O 3 was reduced to Fe at the same time [23,24]. Results showed that methane could reduce iron oxides to metallic iron via partial oxidation over iron oxides [25][26][27][28]. However there was little study on the combination of Fe and methane for NOx reduction, in particular, their effect on characteristics of NO reduction and their interactions were not clearly understood so far.…”

Partial Oxidation of Methane to Nitrogen Free Synthesis Gas Using Air as Oxidant

“…In addition, the chemical changes of oxides during the reaction have not been well understood. We have surveyed several complex metal oxides reactive for reaction (9) and durable for re-oxidation after the reaction, and found that Fe-and Ni-based complex oxides are very active and durable [28,29].…”