%0 Journal Article
%@ 08968446
%A Hassan, M.A.
%A Miyao, T.
%A Komiyama, M.
%D 2019
%F scholars:11814
%I Elsevier B.V.
%J Journal of Supercritical Fluids
%K Batch reactors; Binding energy; Catalysts; Manganese oxide; Methane; Petroleum prospecting; Silica; Sodium compounds; Transition metal oxides; Transition metals; Zirconia, Active surfaces; Catalytically active species; Feed concentration; Methane coupling; Oxidative coupling of methane; Oxidative coupling of methanes (OCM); Supercritical water; ZrO2 synergy, Molecular oxygen
%P 8-13
%R 10.1016/j.supflu.2018.07.001
%T Catalytic oxidative coupling of methane in supercritical water: Investigations on a catalytically active species
%U https://khub.utp.edu.my/scholars/11814/
%V 144
%X Catalyst survey for oxidative coupling of methane (OCM) under supercritical water (SCW) environment at 658 K and 26 MPa using an 8.8-mL batch reactor and H2O2 as a molecular oxygen source was performed at a feed concentration molar ratios of 0.10 CH4/H2O and 0.15 O2/CH4. First and second transition metal oxides (V, Cr, Co, Cu, Zr and Mo) and some lanthanide oxides (La and Ce) showed relatively high OCM activities of ca. 0.5�1  C yield at a very low catalyst loading of 0.05 g. Exploration of catalyst formulations found that oxides of transition metals combined with ZrO2 were effective, with MnO2�ZrO2 showing a high synergy effect giving almost twice as much methane coupling yield. The OCM activity was correlated with the surface amount of a low 1s binding energy (O1s, 526�527 eV) oxygen species on the catalyst, as well as its energy separation from the lattice oxygen. In terms of this oxygen species, SCW-OCM activity of Mn/Na2WO4/SiO2, known as a good gas phase OCM catalyst and also showed a high turnover efficiency for SCW-OCM was further improved by supporting Mn/Na2WO4 on ZrO2 instead of SiO2. © 2018 Elsevier B.V.
%Z cited By 6