CO methanation CO2 reforming CO2-CH4 reforming Cu states Fischer-Tropsch H2 production HY LDPE MCM-41 MnO2 Ni-(Fe/Cr) Ni-based catalyst Ni/MCM-41 catalyst Y zeolite ZSM-5 acid treatment active phase base-free carbon deposition catalyst catalytic pyrolysis cobalt carbide crystal type deactivation density functional theory dimethyl carbonate dimethyl ether dual bed formaldehyde furfural oxidation to furoic acid