Decomposition of cyclohexyl hydroperoxide over bimetallic mesoporous materials containing cobalt and chromium

Abstract

Bimetallic mesoporous Co‐Cr‐TUD‐1 and its counterparts Co‐TUD‐1 and Cr‐TUD‐1 were synthesized by a direct hydrothermal treatment (DHT) method with triethanolamine as a template. The products were characterized by many techniques. Results show that Co and Cr are incorporated into the framework of TUD‐1. The catalytic behaviours of the samples were tested in decomposition of cyclohexyl hydroperoxide (CHHP). Co‐Cr‐TUD‐1 (Si/(Co + Cr) = 25) shows the highest catalytic efficiency with a CHHP conversion of 96.9 % and total selectivity of cyclohexanone and cyclohexanol of 95.9 %, which outperforms Co‐TUD‐1 and Cr‐TUD‐1 and indicates a synergistic effect between Co and Cr in Co‐Cr‐TUD‐1. The catalysts are mainly heterogeneous as shown in various experiments, while the catalytic performances of recovered catalysts declined modestly, indicating non‐negligible amounts of Co and Cr are leached after some cycles.

Experimental methods in chemical engineering: Ultraviolet visible spectroscopy—UV‐Vis

“…Chemical engineering applications include waste‐water treatment, dye degradation, characterizing colloidal nanoparticles—silver, gold, and copper—metallic coordination of molybdenum and cobalt, bimetallic mesoporous materials with cobalt and chromium, and composites of graphene oxide and silver nanoparticles …”

Organic Acid Anions Modified α-Co(OH)2 with Enhanced Activity for the Decomposition of Cyclohexyl Hydroperoxide

“…Recent works were devoted to exploring new catalyst for effectively decomposing CHHP in absence of alkali medium. − Cerium oxides with various shapes and particle sizes have been used as catalysts for CHHP decomposition . Mono- and dinuclear vanadium complexes have been identified as very promising homogeneous catalysts for CHHP decomposition .…”

Selective Decomposition of Cyclohexyl Hydroperoxide using Homogeneous and Heterogeneous CrVI Catalysts: Optimizing the Reaction by Evaluating the Reaction Mechanism

“…Therefore, another approach to use the high activity and in particular to benefit from high selectivity is the use of heterogeneous chromium(VI) catalysts . Besides chromium species supported on zeolites and mesoporous chromium aluminophosphates (CrAlPO‐5), the oxidation of cyclohexane as well as the selective decomposition of cyclohexyl hydroperoxide have been investigated extensively with polymer‐supported transition metal catalysts . For example, following the activity of soluble cobalt catalysts, poly(4‐vinylpyridine) (PVP) supported Co II catalysts have been prepared and investigated for the oxidation of cyclohexane .…”

“…Besides chromium species supported on zeolites and mesoporous chromium aluminophosphates (CrAlPO‐5), the oxidation of cyclohexane as well as the selective decomposition of cyclohexyl hydroperoxide have been investigated extensively with polymer‐supported transition metal catalysts . For example, following the activity of soluble cobalt catalysts, poly(4‐vinylpyridine) (PVP) supported Co II catalysts have been prepared and investigated for the oxidation of cyclohexane . In the same way, CrO 3 immobilized on PVP was prepared for the selective decomposition of cyclohexyl hydroperoxide and seemed to be a promising candidate for this kind of reaction .…”