Kinetics of nitrobenzene hydrogenation using a gel entrapped palladium catalyst

Abstract

Palladium metal has been precipitated in a gel formed by the crosslinking polymerization of 2-hydroxyethylmethacrylate. The metal particles were found to have an average size of 14 nm. The dried polymer gel contained 1.38% Pd; it was cmshed and sieved to give gel particles ca 200 p. m in size. When the gel containing Pd was swollen by a solvent, catalytic activity toward the quantitative hydrogenation of nitrobenezene to aniline was observed. A detailed study of the kinetics of this hydrogenation revealed that at 101 kPa pressure and 31"C, resistance to the reaction was approximately equally divided between extra-particle mass transfer and the chemical activity of the Pd. The high activity of this novel catalyst is attributed to the large surface of the Pd and the extensive swelling of the gel by the reaction medium.ydrogenation catalysts of the platinum group

Three-Phase Nitrobenzene Hydrogenation over Supported Glass Fiber Catalysts: Reaction Kinetics Study

“…The linear regression line illustrates that the pressure dependence fits the Eley-Rideal equation. That the trend line does not tend to intercept at zero is in agreement with the experimental results obtained by Tong et al [5]. The reaction rate was observed to increase sharply for low hydrogen pressures and slowly for higher partial hydrogen pressures.…”

An automated flow platform for accurate determination of gas–liquid–solid reaction kinetics

“…The results illustrate that the pre-exponential factors are 4.183 × 10 5 L mol −1 min −1 for AMS and 1.636 × 10 8 L mol −1 min −1 for NB. The activation energies are 23.4 kJ mol −1 for AMS and 40.9 kJ mol −1 for NB which are consistent with the studies for AMS (20.9-31.8 kJ mol −1 ) 59,60 and for NB (35.1-47.7 kJ mol −1 ), [61][62][63] respectively, as shown in Table 2.…”

Liquid phase hydrogenation of nitrobenzene

“…Palladium [9][10][11][12][13], platinum [14] and nickel [6,[15][16][17] catalysts are often used. Although palladium catalysts are most expensive, they are often applied at low and medium temperatures (up to 200 °C), as palladium is highly selective for reduction of functional groups attached directly or onto the side chains of aromatic compounds without touching altering the aromatic ring [18].…”