TY - JOUR

T1 - Cyclohexene oxidation with h 2 o 2 over metal-organic framework mil-125(Ti)

T2 - The effect of protons on reactivity

AU - Maksimchuk, Nataliya

AU - Lee, Ji Sun

AU - Ayupov, Artem

AU - Chang, Jong San

AU - Kholdeeva, Oxana

PY - 2019/4/1

Y1 - 2019/4/1

N2 - The catalytic performance of the titanium-based metal-organic framework MIL-125 was evaluated in the selective oxidation of cyclohexene (CyH) with environmentally friendly oxidants, H 2 O 2 and t BuOOH. The catalytic activity of MIL-125 as well as the oxidant utilization efficiency and selectivity toward epoxide and epoxide-derived products can be greatly improved by acid additives (HClO 4 or CF 3 SO 3 H). In the presence of 1 molar equivalent (relative to Ti) of a proton source, the total selectivity toward CyH epoxide and trans-cyclohexane-1,2-diol reached 75-80% at 38-43% alkene conversion after 45 min of reaction with 1 equivalent of 30% H 2 O 2 at 50 °C. With 50% H 2 O 2 as the oxidant, the total selectivity toward heterolytic oxidation products increased up to 92% at the same level of alkene conversion. N 2 adsorption, powder X-ray diffraction (PXRD), and infrared (IR) spectroscopy studies before and after the catalytic oxidations confirmed the absence of structural changes in the Metal-organic framework (MOF) structure. MIL-125 was stable toward titanium leaching, behaved as a truly heterogeneous catalyst, and could easily be recovered and reused several times without any loss of the catalytic properties.

AB - The catalytic performance of the titanium-based metal-organic framework MIL-125 was evaluated in the selective oxidation of cyclohexene (CyH) with environmentally friendly oxidants, H 2 O 2 and t BuOOH. The catalytic activity of MIL-125 as well as the oxidant utilization efficiency and selectivity toward epoxide and epoxide-derived products can be greatly improved by acid additives (HClO 4 or CF 3 SO 3 H). In the presence of 1 molar equivalent (relative to Ti) of a proton source, the total selectivity toward CyH epoxide and trans-cyclohexane-1,2-diol reached 75-80% at 38-43% alkene conversion after 45 min of reaction with 1 equivalent of 30% H 2 O 2 at 50 °C. With 50% H 2 O 2 as the oxidant, the total selectivity toward heterolytic oxidation products increased up to 92% at the same level of alkene conversion. N 2 adsorption, powder X-ray diffraction (PXRD), and infrared (IR) spectroscopy studies before and after the catalytic oxidations confirmed the absence of structural changes in the Metal-organic framework (MOF) structure. MIL-125 was stable toward titanium leaching, behaved as a truly heterogeneous catalyst, and could easily be recovered and reused several times without any loss of the catalytic properties.

KW - Alkene

KW - Epoxidation

KW - Heterogeneous catalysis

KW - Hydrogen peroxide

KW - Metal-organic framework

KW - MIL-125

KW - Titanium

KW - SELECTIVE OXIDATION

KW - heterogeneous catalysis

KW - titanium

KW - hydrogen peroxide

KW - TITANIUM

KW - EPOXIDATION

KW - metal-organic framework

KW - P-BENZOQUINONES

KW - epoxidation

KW - PHOTOCATALYTIC ACTIVITY

KW - TI

KW - alkene

KW - OLEFINS

KW - HYDROGEN-PEROXIDE

KW - DESULFURIZATION

KW - HETEROGENEOUS CATALYSTS

UR - http://www.scopus.com/inward/record.url?scp=85065395857&partnerID=8YFLogxK

U2 - 10.3390/catal9040324

DO - 10.3390/catal9040324

M3 - Article

AN - SCOPUS:85065395857

VL - 9

JO - Catalysts

JF - Catalysts

SN - 2073-4344

IS - 4

M1 - 324

ER -