Table 2.

Promising metal catalysts for supercritical water gasification of complex organic feedstocks.

Catalyst/support	Synthesis method	Properties & performance	Source
Ru/γ-Al2O3	Commercially obtained	Highest catalytic activity for gasification of alkylphenols; decreased activity after transition from γ- to α-phase alumina; high activity for C-C bond cleavage	[18, 100, 103, 104, 108, 109]
Ru/TiO2	Commercially obtained	Highest catalytic activity for gasification of lignin; high activity for C-C bond cleavage	[110, 111, 112]
RuO2	Commercially obtained	Conversion superior to catalysis by NiO, MoO3, and ZrO2	[105]
Ru/C	Commercially obtained	High catalytic activity; decreased activity after repetitive use	[109, 110]
Ni/γ-Al2O3	Incipient wetness impregnation; Ni(NO3)2‧6H2O precursor	Highest catalytic activity and H2 selectivity of 17 supported transition metal catalysts tested for SCWG of glucose in [18]	[18, 100]
Ni/SiO2	Evaporative deposition; Ni(NO3)2‧6H2O precursor	High H2 selectivity; high activity for C-C bond cleavage	[113]
Pt/SiO2	Ion exchange at pH = 11; Pt(NH4)4(NO3)2 precursor	High H2 selectivity; moderate activity for C-C bond cleavage; low methanation rate	[113]
CuO	In-situ hydrothermal generation of nanoparticles; Cu(CH3COO)2 precursor	High S/V ratio; effective catalyst for methanol reforming; not effective for cleaving C-C bonds of larger molecules	[107]