title: Reactivity of heteropolytungstate and heteropolymolybdate metal transition salts in the synthesis of dimethyl carbonate from methanol and CO₂.
abstract: A series of Keggin-type heteropoly compounds (HPC) having different countercations (Co, Fe) and different addenda atoms (W, Mo) were synthesized and characterized by means of Fourier-Transform Infrared Spectrometer (FT-IR) and X-ray powder diffraction (XRD). The catalytic properties of the prepared catalysts for the dimethyl carbonate (DMC) synthesis from CO(2) and CH(3)OH were investigated. The experimental results showed that the catalytic activity is significantly influenced by the type of the countercation and addenda atoms transition metal. Among the catalysts examined, Co(1.5)PW(12)O(40) is the most active for the DMC synthesis, owing to the synergetic effect between Co and W. Investigating the effect of the support showed that the least acidic one (Al(2)O(3)) enhanced the conversion but decreased the DMC selectivity in favor of that of methyl formate (MF), while that of dimethoxy methane remained stable.
authors: Department of Chemistry, King Saud University, P. O. Box 2455, Riyadh 11451, Saudi Arabia.
authors: Ahmed
authors: A
authors: Aouissi
authors: Salem S
authors: SS
authors: Al-Deyab
authors: Ahmad
authors: A
authors: Al-Owais
authors: Amro
authors: A
authors: Al-Amro
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry*; D002384:Catalysis; D005561:Formates / Q000138:chemical synthesis*; D008670:Metals / Q000737:chemistry*; D000432:Methanol / Q000737:chemistry*; D012492:Salts / Q000737:chemistry*; D028561:Transition Elements
chemical_list: D005561:Formates; D008670:Metals; D012492:Salts; D028561:Transition Elements; D002245:Carbon Dioxide; C023025:methyl carbonate; D000432:Methanol