Transition metal chloride catalyzed methanol gasification in supercritical water: Experimental and DFT studies

Experimental analysis and density functional theory (DFT) calculation were performed on methanol gasification catalyzed by transition metal chlorides (CdCl2, CuCl2, FeCl3, and NiCl2) in supercritical water. The reaction temperatures (550-625 & DEG;C), residence times (6 -60 s), and catalyst concentrations (0.00025-0.001 mol L-1) were experimentally investigated using a continuous reactor. Non-catalytic gasification of methanol produced the H2 yield of 0.64 mol mol-1 and gasification efficiency (GE) of 28.42 wt%, while the addition of 0.0005 mol L-1 transition metal chlorides contributed to significantly improved H2 yield and GE of 1.17-1.16 mol mol-1 and 61.13-106.16 wt% at 575 & DEG;C, respectively. The water molecules decrease the overall energy barrier of methanol decomposition pathways to promote methanol hydrogenation by forming intermolecular hydrogen bonds. Different transition metal cations form coordinate bond force with the O atom of the hydroxy group, causing a 20.5-41.1% reduction in the energy barrier of methanol oxidation and promoting methanol decomposition.& COPY; 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

The catalytic gasification of methanol by transition metal chlorides in supercritical water was studied. The addition of transition metal chlorides significantly improved the hydrogen yield and gasification efficiency, while water molecules decreased the energy barriers of methanol decomposition pathways and different transition metal cations promoted methanol decomposition by forming coordinate bond force with hydroxy group oxygen atom.