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Two type zirconia(monoclinic and tetragonal phase ZrO_2) carriers were synthesized via hydrothermal route,and nano-sized zirconia supported nickel catalysts were prepared by incipient impregnation then followed thermal treatment at 300℃ to 500℃,for the CO_2 selective hydrogenation to synthetic natural gas(SNG).The catalysts were characterized by XRD,CO_2-TPD-MS,XPS,TPSR(CH_4,CO_2) techniques.For comparison,the catalyst NZ-W-400(monoclinic) synthesized in water solvent exhibited a better catalytic activity than the catalyst NZ-M-400(tetragonal) prepared in methanol solvent.The catalyst NZ-W-400 displayed more H_2 absorbed sites,more basic sites and a lower temperature of initial CO_2 activation.Then,the thermal treatment of monoclinic ZrO_2 supported nickel precursor was manufactured at three temperature of 350,400,500℃.The TPSR experiments displayed that there were the lower temperature for CO_2 activation and initial conversion(185℃) as well as the lower peak temperature of CH_4 generation(318℃),for the catalyst calcined at 500℃.This sample contained the more basic sites and the higher catalytic activity,evidenced byCO_2-TPD-MS and performance measurement.As for the NZ-W-350 sample,which exhibited the less basic sites and the lower catalytic activity,its initial temperature for CO_2 activation and conversion was higher(214℃) as well as the higher peak temperature of CH_4 formation(382℃).
Two type zirconia (monoclinic and tetragonal phase ZrO 2) carriers were synthesized via hydrothermal route, and nano-sized zirconia supported nickel catalysts were prepared by incipient impregnation then followed by thermal treatment at 300 ° C to 500 ° C for the CO 2 selective hydrogenation to synthetic natural gas (SNG) .The catalysts were characterized by XRD, CO_2-TPD-MS, XPS, TPSR (CH_4, CO_2) techniques. For comparison, the catalyst NZ-W- the catalyst NZ-M-400 (tetragonal) prepared in methanol solvent. catalyst NZ-W-400 displayed more H 2 absorbed sites, more basic sites and a lower temperature of initial CO 2 activation. Chen, the thermal treatment of monoclinic ZrO 2 supported nickel precursor was manufactured at three temperature of 350,400,500 ° C. The TPSR experiments displayed that there were the lower temperature for CO 2 activation and initial conversion (185 ° C) as well as the lower peak temperature of CH _4 generation (318 ° C) for the catalyst calcined at 500 ° C. This sample contained the more basic sites and the higher catalytic activity, evidenced by CO_2-TPD-MS and performance measurement. As for the NZ-W- the less basic sites and the lower catalytic activity, its initial temperature for CO 2 activation and conversion was higher (214 ° C) as well as the higher peak temperature of CH 4 formation (382 ° C).