02191nas a2200277   4500008004100000022001400041245012300055210006900178260000900247300001600256490000700272520125600279653001601535653002501551653002401576653003001600653002101630100002301651700002101674700002001695700000501715700001601720700002301736700002301759856013101782       2021                        eng d  a2155-543500aDirect oxidation of cyclohexane to adipic acid by a WFeCoO(OH) catalyst: role of bronsted acidity and oxygen vacancies0 aDirect oxidation of cyclohexane to adipic acid by a WFeCoOOH cat  cSEP   a10754-107660 v113 aThis work reports the catalytic activity of the trimetallic mixed-metal oxyhydroxide WFeCoO(OH) for the direct oxidation of cyclohexane to adipic acid (AA) without the use of concentrated HNO3. WFeCoO(OH) displayed a 40% conversion of cyclohexane and a 67% selectivity to AA under relatively milder conditions of temperature (90 degrees C) and pressure (1 atm). Experimental evidence confirmed the presence of acidic, basic, and redox sites on WFeCoO(OH). The detailed investigation revealed that doping W in the Co-FeO(OH) matrix increased the amount of surface lattice oxygen (OS-L) and caused a significant surge in acidity (5.1 mmol/g). The calculated deprotonation energy of WFeCoO(OH) was 1434 kJ/mol, and the trend in acidity was WCoO(OH) < WFeCoO(OH) < FeCoO(OH) similar to CoO(OH). Energy calculations showed that WFeCoO(OH) had a high propensity to generate oxygen vacancies by the loss of either a water molecule or an oxygen atom (-132.2 or -140.9 kJ/mol, respectively). Basicity was generated due to the presence of conjugate pairs of the surface hydroxyl groups. The combined action of the trifunctional acidic, basic, and redox-active metal centers along with the oxygen vacancies was responsible for the enhanced catalytic performance.10aAdipic Acid10adeprotonation energy10ametal oxyhydroxides10amultifunctional catalysts10aoxygen vacancies1 aVernekar, Dnyanesh1 aDayyan, Mohammad1 aRatha, Satyajit1 a1 aHaider, Ali1 aKhan, Tuhin, Suvra1 aJagadeesan, Dinesh  uhttps://library.ncl.res.in/content/direct-oxidation-cyclohexane-adipic-acid-wfecoooh-catalyst-role-bronsted-acidity-and-oxygen