Characterization of Supported NiSO4 and Effect of TiO2–ZrO2 Composition on Catalytic Activity for Acid Catalysis

Abstract

A series of catalysts, NiSO 4 /TiO 2 -ZrO 2 having different TiO 2 -ZrO 2 composition, for acid catalysis was prepared by the impregnation method using an aqueous solution of nickel sulfate. The addition of TiO 2 to ZrO 2 improved the surface area of the catalyst and enhanced its acidity remarkably because of the formation of new acid sites through the charge imbalance of Ti-O-Zr bonding. The binary oxide, TiO 2 -ZrO 2 calcined above 600°C resulted in the formation of crystalline orthorhombic phase of ZrTiO 4 . Therefore, NiSO 4 /TiO 2 -ZrO 2 calcined at 500°C exhibited a maximum catalytic activity for acid catalysis, and then the catalytic activity decreased with the calcination temperature. The correlation between catalytic activity and acidity held for both reaction, 2-propanol dehydration and cumene dealkylation. NiSO 4 supported on 50TiO 2 -50ZrO 2 (TiO 2 /ZrO 2 ratio = 1) among TiO 2 -ZrO 2 binary oxides exhibited the highest catalytic activity for acid catalysis.

Low-Temperature Sol−Gel Preparation of Ordered Nanoparticles of Tungsten Carbide/Oxide

“…The material was heated at 100 °C for 1 h under nitrogen before measurements were taken. The surface area of the nitrogen molecule was taken to be 0.162 nm 2 . Attempts to perform thermogravimetric and differential thermal analysis (TGA/DTA) were made but failed due to the large increase in volume of the dry gel material on pyrolysis and damaging the instrument.…”

“…Hudson et al describe the preparation of nonstoichiometric metal oxides such as oxygen-deficient WO 2.72 needles . Such materials have significant application in a number of fields such as catalysis, gas sensing, and electrochemistry . They have also been used as precursors for the synthesis of inorganic fullerene-type materials based on 2H−WS 2 -layered chalcogenides .…”

“…Flow diagram for the preparation of nanoscopic tungsten carbide.Na 2 WO 4 + HCl ) H 2 WO 4 + 2NaCl(1)poly(acrylic acid) on pyrolysis ) C + organic material(2) …”

Cracking of cumene on tungsten promoted ceria catalysts

“…The use of liquid phase acid catalysts suffers from different drawbacks such as difficulty in separation of the catalysts from the product stream, requirement of large amount of catalyst, and disposal of the solid waste formed during the reaction. Furthermore, the cost of process installation and maintenance is high since the liquid acids are highly corrosive [4]. Thus, the search for environmentally benign catalysts has driven the research of new materials as a substitute for the liquid phase acid catalysts.…”