Simple selective hydrogenation of benzene to cyclohexene in the presence of sodium dicyanamide

Abstract

A new catalyst system was used in the liquid phase hydrogenation of benzene to cyclohexene containing only an aqueous solution of Ru/La 2 O 3 and a very small quantity of sodium dicyanamide (NaDCA). This additive considerably improves the catalyst performance compared to DCA based ionic liquids. The effects of the amount of NaDCA and metal loading of the catalyst were investigated and a high initial selectivity to cyclohexene of 70% was reached.

Continuously Conducted Selective Hydrogenation of Benzene to Cyclohexene in a Four‐Phase System

“…It is to be noted that the system generally requires, next to water, ZnSO 4 as additive to obtain cyclohexene in high selectivities and yields. dicyanamide (NaDCA) leads to high selectivities (80 %) at low conversions (10 %) as shown by our group [2,12].…”

Heterophase-structured nanocrystals as superior supports for Ru-based catalysts in selective hydrogenation of benzene

“…All reactions were carried out under a kinetically-controlled regime, which is demonstrated in section of Mass-Transfer Considerations . The reaction conditions adopted here are typical for selective hydrogenation of benzene2526272829303132333435. The reaction process was monitored by discharging ~0.5 mL of the reaction mixture at periodic 5 min followed by analysis on a gas chromatography with a FID detector.…”

“…Currently, Ru-based catalysts are the most effective, but they always tend to produce cyclohexane with high activity. Many developments of Ru-based heterogeneous catalysts are trying to solve this long-standing problem252627282930. Most studies have enhanced the selectivity via tuning and controlling the catalytic active components, co-catalysts, and additives313233343536.…”

“…Most studies have enhanced the selectivity via tuning and controlling the catalytic active components, co-catalysts, and additives313233343536. A common view in most researches is that the hydrophilic/hydrophobic properties of the catalysts or supports are of great concern252627282930313233343536. To date, relatively little attention has been given to constructing the heterophase structures of the catalysts and tuning the phase structure of supports for more appropriate surface compatibility12.…”

Performance of Ru/La2O3–ZnO Catalyst for the Selective Hydrogenation of Benzene to Cyclohexene

“…The catalyst is developing a hydrate shell that prevents re-adsorption of the formed cyclohexene because of inferior solubility of cyclohexene in water compared to benzene (factor of 6 at 150 °C, 50 bar) [6]. In previous studies performed by our group [6,7], we developed a process that does not use large amounts of these inorganic salts as additives but rather applies minimal amounts of the salt NaDCA (sodium dicyanamide).…”