Ni10.7YxWy/γ-Al2O3催化剂在甲烷干重整反应中的抗积碳性能

Carbon deposition resistance of Ni_(10.7)Y_xW_y/γ-Al_2O_3 catalysts in methane dry reforming reaction

采用等体积浸渍法制备了一系列Ni_(10.7)Y_xW_y/γ-Al_2O_3催化剂,用于甲烷二氧化碳干重整(DRM)反应,通过XRD、BET、H_2-TPR、TPH、HRTEM和XPS对催化剂进行了表征,考察了金属助剂对催化剂性能的影响。实验结果表明,添加钇使NiAl_2O_4的还原程度增强且能促进活性组分Ni的分散,添加钇和钨可使催化剂的比表面积、孔径和孔体积均减小。同时添加钨和钇的Ni_(10.7)Y_3W_(10)/γ-Al_2O_3催化剂的稳定性最好。在DRM反应过程中,Y_2O_3与CO_2作用形成Y_2O_2CO_3能抑制丝状碳的生成,从而提高催化剂的活性和稳定性。Ni_(10.7)W_(10)/γ-Al_2O_3催化剂在DRM反应过程中发生W碳化反应生成α-WC,与活性组分Ni形成双活性位点,从而提高了催化剂的活性和稳定性。Ni_(10.7)Y_3W_(10)/γ-Al_2O_3催化剂不仅生成了双活性位点,还有效抑制了积碳的扩散,从而抑制了丝状碳的生成。

A series of Ni10.7YxWy/γ-Al2O3 catalysts were prepared by incipient wetness impregnation for dry reforming of methane(DRM)reaction with carbon dioxide.The effects of metal promoters on catalyst performance were investigated by XRD,BET,H2-TPR,TPH,HRTEM and XPS.The results showed that the addition of yttrium enhanced the degree of reduction of NiAl2O4 and promoted the dispersion of the active component Ni.The addition of yttrium and tungsten could reduce the specific surface area,pore size and pore volume of the catalyst.The stability of the Ni10.7Y3W10/γ-Al2O3 catalyst was the best.During the DRM reaction,the formation of Y2O2CO3 by the interaction of Y2O3 and CO2 could inhibit the formation of filamentous carbon,thereby improving the activity and stability of the catalyst.The Ni10.7W10/γ-Al2O3 catalyst underwent W carbonization reaction to formα-WC during the DRM reaction,which formed a double active site with the active component Ni,thereby improving the activity and stability of the catalyst.The Ni10.7Y3W10/γ-Al2O3 catalyst not only generated double active sites,but also effectively inhibited the diffusion of carbon deposits,thereby inhibiting the formation of filamentous carbon.