Selective hydrogenation of 2-butyne-1,4-diol to 2-butene-1,4-diol: roles of ammonia, catalyst pretreatment and kinetic studies

• Published in: Applied catalysis. A, General Vol. 216; no. 1; pp. 13 - 22
• Main Authors: Telkar, M.M., Rode, C.V., Rane, V.H., Jaganathan, R., Chaudhari, R.V.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.08.2001; Elsevier
• Subjects: 2-Butene-1, 4-diol; 2-Butyne-1, 4-diol; Catalysis; Catalyst pretreatment; Catalytic reactions; Chemistry; Exact sciences and technology; General and physical chemistry; Kinetics; Palladium supported catalysts; Role of ammonia; Selective hydrogenation; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; 2-Butyne-1, 4-diol; Role of ammonia; Selective hydrogenation; 2-Butene-1, 4-diol; Catalyst pretreatment; Palladium supported catalysts; Kinetics; Diol; Acetylenic compound; Magnesium Carbonates; Transition metal; Carbon; Hydrogenation; Barium Carbonates; Supported catalyst; Ammonia; Calcium Carbonates; Pretreatment; Platinoid; Alumina; Catalyst; Catalyst support
• ISSN: 0926-860X; 1873-3875
• DOI: 10.1016/S0926-860X(01)00547-6

The selective hydrogenation of 2-butyne-1,4 diol to cis-2-butene-1,4 diol has been studied using different palladium-supported catalysts. With 1% Pd/C catalyst, the major product formed was 1,4-butanediol, along with other side products such as butenediol, γ-hydroxy butyraldehyde, n-butyraldehyde and n-butanol. Role of supports and ammonia was very significant in achieving a high selectivity to the intermediate, 2-butene-1,4-diol. A selective hydrogenation of 2-butyne-1,4-diol to give cis-2-butene-1,4-diol was achieved using 1% Pd/CaCO 3–NH 3 catalyst system. Effects of catalyst pretreatment with both 2-butyne-1,4-diol and H 2 on the catalyst activity and selectivity were investigated. It was found that the catalyst activity increased substantially, while the selectivity to 2-butene-1,4-diol decreased slightly with hydrogen-pretreated catalyst. The effects of hydrogen pressure, catalyst loading, initial concentrations of 2-butyne-1,4-diol and ammonia on the initial rate of hydrogenation were also studied in a batch reactor in a temperature range of 323–353 K. All the data obtained were in the kinetic regime under the conditions of the present work, based on which a Langmuir–Hinshelwood (L–H) type rate model was proposed. To verify the applicability of the kinetic model over a wide range of conditions, a batch reactor model was also developed. The agreement between the predicted concentration vs. time profiles with the experimental results was excellent.