Modifying alumina with CaO or MgO in supported Ni and Ni–Co catalysts and its effect on dry reforming of CH4

• CaO and MgO modified and unmodified catalysts characterized and tested for DRM.
• Additional active sites were detected when support was modified with CaO.
• Better catalytic activity and less carbon observed for CaO modified catalysts.
• Additional active sites appear to be responsible for improved catalytic behavior.
• MgO interacted strongly with Ni and Co adversely affecting catalytic activity.

Modifying the support of the alumina (Al2O3) supported Ni and Ni–Co catalysts with limited amounts of CaO and MgO had an effect on the catalytic activity during the reforming of CH4 with CO2 at 873 K. The presence of CaO had a favorable effect on the catalytic activity of the supported catalysts. In contrast, the presence of MgO had an adverse effect due to the strong interaction of MgO with the Ni and Co phases under the present synthesis conditions. Characterization of the supported Ni and Ni–Co catalysts revealed that modifying the support with CaO or MgO had an effect on the reducibility, amount and type of H2 and CO2 chemisorbed and the nature of the metal crystallite. The characterization studies also revealed that the limited interaction of CaO with Ni phase in supported Ni and Ni–Co catalysts gave rise to additional sites that were able to chemisorb H2 and CO2 at higher temperatures without having a significant effect on the reducibility of the catalysts. The presence of these additional sites may be the reason for the improved activity of the modified-Al2O3 supported Ni and Ni–Co catalysts containing CaO.

Figure optionsDownload as PowerPoint slide