Effect of calcium salts on isosynthesis over ZrO2 catalysts

✍ Scribed by Yingwei Li; Dehua He; Zhenxing Cheng; Caili Su; Junrong Li; Qiming Zhu

• Book ID: 104421545
• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 166 KB
• Volume: 175
• Category: Article
• ISSN: 1381-1169
• DOI: 10.1016/s1381-1169(01)00233-3

✦ Synopsis

The promoting effects of various calcium salts on the activity and selectivity of ZrO 2 in isosynthesis were studied in this work. Calcium salts were added into zirconia by mechanical mixing methods. Catalytic tests were performed under relatively mild operation conditions (673 K, 650 h -1 , 5.0 MPa). CaF 2 and CaSO 4 were found to be effective additives, which could remarkably enhance the i-C 4 selectivity in total hydrocarbons while maintaining the activity of pure ZrO 2 when being added into zirconia. However, Ca(NO 3 ) 2 , Ca(BO 2 ) 2 and CaCl 2 wholly changed the distribution of hydrocarbons to favor the methanation. The results of temperature-programmed desorption (TPD) of NH 3 and CO 2 indicated that the performance of the catalysts depended on the acid-base properties of the catalysts. The appropriate amount of acid and base and the ratio of the basic to acidic sites on the catalysts are significant for the synthesis of i-C 4 hydrocarbons from CO hydrogenation.