Activity and selectivity of palladium catalysts during the liquid-phase hydrogenation of phenol. Influence of temperature and pressure

Journal Article · Sat Apr 01 04:00:00 EST 1995 · Industrial and Engineering Chemistry Research

DOI:https://doi.org/10.1021/ie00043a004· OSTI ID:63137

Gonzalez-Velasco, J R; Gonzalez-Marcos, M P; Arnaiz, S; Gutierrez-Ortiz, J I; Gutierrez-Ortiz, M A ^[1]

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1. Univ. del Pais Vasco, Bilbao (Spain)

Two series of highly dispersed palladium catalysts supported on alumina have been prepared by adsorption from solution, with palladium contents varying from 0.25 to 2.0 wt %. The first series was calcined at 773 K for 4 h in air, whereas the second series was just heated at 423 K for 1 h in nitrogen, before reduction. Complete dispersion of the metal has been found for the calcined catalysts, and metal dispersion was favored with low palladium contents for the noncalcined catalysts. The kinetic behavior of the catalysts has been analyzed for the liquid-phase hydrogenation of phenol in a stirred tank reactor, ensuring a chemically controlled regime for stirring speed above 750 rpm and catalyst particle below 0.08--0.16 mm in the studied conditions. Despite their higher metallic dispersion, the calcined catalysts presented lower activity than their corresponding noncalcined catalysts. The influence of hydrogen partial pressure on activity showed a reaction order of 2. The apparent activation energy resulted in 56.8 kJ/mol. Selectivity to cyclohexanone was found to be very high for all experiments. Some conclusions on the kinetic reaction rate equations and the apparent activation energies of phenol to cyclohexanone and cyclohexanone to cyclohexanol are given.

• Sponsoring Organization: USDOE
• OSTI ID: 63137
• Journal Information: Industrial and Engineering Chemistry Research, Journal Name: Industrial and Engineering Chemistry Research Journal Issue: 4 Vol. 34; ISSN IECRED; ISSN 0888-5885
• Country of Publication: United States
• Language: English

Related Subjects

10 SYNTHETIC FUELS
ALUMINIUM OXIDES
CATALYST SUPPORTS
CATALYTIC EFFECTS
CHEMICAL FEEDSTOCKS
CHEMICAL PREPARATION
CYCLOHEXANOL
HYDROGENATION
PALLADIUM
PHENOL
PRESSURE DEPENDENCE
SYNTHESIS
TEMPERATURE DEPENDENCE