The Synthesis of Carbamate from the Reductive Carbonylation of Nitrobenzene Over Pd-based Catalysts Department of Chemical Engineering, The University of Akron, Akron, OH 44325-

Department of Chemical Engineering, The University of Akron, Akron OH

44325-3906

schuang@uakron.edu Abstract Pd/Al2O3-FeCl3, and Ce-Pd/Al2O3-FeCl3 catalysts exhibit activity for the synthesis of ethylphenylcarbamate from the reductive carbonylation of nitrobenzene with ethanol at 453 K and 2.07 – 2.93 MPa. The advantage of the use of Al2O3-supported Pd catalyst is the easy of catalyst recovery form the reactants/product mixture. Introduction Isocyanates are important chemical feedstock for the manufacture of fertilizers, pesticides, and various forms of polyurethane (1-4). The current isocyanate synthesis process involves phosgenation of amines. RNH2 + COCl2 → RNCO + HCl [1] where R is an alkyl or aryl group. The phosgenation process suffers from the difficulty in handling hazardous phosgene as well as the highly corrosive byproduct HCl. To minimize the environmental impact of COCl2, extensive research has been directed toward the development of effective catalysts for oxidative and reductive carbonylation (1-16). Oxidative carbonylation: RNH2 + R'OH + CO + 1/2O2 → RNHCOOR' + H2O [2] Reductive carbonylation: RNO2 + 3CO + R'OH → RNHCOOR' + 2CO2 [3] Thermal decomposition: RNHCOOR' → RNCO (isocyanate) + R'OH [4] where R and R' are either alkyl or phenyl groups.