CO₂/O₂-enhanced ethane dehydrogenation over a sol–gel synthesized Ni/ZrO₂–MgO nanocatalyst: Effects of Mgo, ZrO_2,and NiO on the catalytic performance

ABSTRACT

A series of catalysts synthesized via the sol–gel method to study the effect of ZrO₂ and MgO and their mixture in ethane dehydrogenation over the Ni/ZrO₂–MgO nanocatalyst in the presence of CO₂/O₂. The catalysts were characterized by XRD, FESEM, EDX, FTIR, and BET techniques. The homogenous dispersion of applied elements in the structure and on the surface of all synthesized catalysts was clear according to the XRD and EDX results, respectively. Synthesized ZrO₂ formed small crystallites while MgO as a high crystalline material depicted large crystallites on the surface. Having these two in the ZrO₂–MgO mixture controlled the observed large crystallite size of MgO and the particle size of the catalyst. The mixture of MgO and ZrO₂ having both beneficial basic and acidic properties resulted in the better catalyst compared to ZrO₂ and MgO. Finally, evaluating the effect of having NiO in the mixture of ZrO₂–MgO confirmed the significant impact of Ni-based catalysts in oxidative dehydrogenation of ethane. Of course, these phases affected all together on the observed results. This cooperation mentioned as the synergistic effect in this study. The best catalyst among the studied ones was Ni/ZrO₂–MgO that demonstrated an ethylene yield of 55.2%.

KEYWORDS:

• Ethane/ethylene
• MgO
• Ni/ZrO₂–MgO
• oxidative dehydrogenation
• sol–gel
• ZrO₂