The CO2-selective facilitated transport membranes based on cross-linked poly(vinyl alcohol) (PVA) and sulfonated polybenzimidazole (SPBI) matrixes were synthesized and characterized for high-pressure synthesis gas purification. The crosslinked PVA-based membranes showed CO2/H-2 selectivity higher than 30 and CO2 permeability as high as close to 1000 barrers for a membrane thickness of 15-30 mu m at a feed pressure of 220 psia, which are desirable for the intended gas purification. The SPBI-based membranes generally showed lower separation performance because of their lower hydrophilicity. The cross-linked PVA-based membranes showed the best separation performance at 106 degrees C. However, the SPBI-I copolymer-based membranes exhibited the best separation performance at 100 degrees C because of also their lower hydrophilicity.