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-oxygen02006nas a2200241   4500008004100000022001400041245009800055210006900153260000800222300001400230490000700244520120700251100001701458700001801475700002301493700002101516700002301537700002401560700002201584700001601606700001801622856012401640       2026                        eng d  a2044-475300aDirect conversion of methane to formic acid over Au-Fe-NaZSM-5 at ambient pressure using H2O20 aDirect conversion of methane to formic acid over AuFeNaZSM5 at a  cMAR  a1797-18050 v163 a<p>
	Direct conversion of methane to value-added products is a long-standing challenge. This report presents the one-step conversion of methane to oxygenates using H2O2 as an oxidant over an Au and Fe supported on NaZSM-5 (0.1Au0.1FeNZ) catalyst, which produces 4264 mu mol of oxygenates with 89% selectivity toward formic acid at 10 bar and 60 degrees C within 30 min in a batch process. The catalyst also produces 26.5 mu mol of oxygenates with 70% selectivity for formic acid at atmospheric pressure and 80 degrees C in a continuous flow process over 9 h of reaction time, making it the first report of such a process. The synergistic interaction of Au and Fe, with the crucial role of Na ions in the zeolite framework in driving the reaction, is revealed through various characterization tools like TEM, XPS, and XAS. Theoretical studies elucidate the active sites responsible for lowering the activation barrier for the crucial C-H activation step. Thus, the catalyst enables the conversion of methane into formic acid with high activity and selectivity, offering new possibilities for harnessing this potent greenhouse gas under process-friendly conditions that were previously unexplored.</p>
1 aKumar, Pawan1 aAhangar, Iqra1 aKesarwani, Srishti1 aUrkude, Rajashri1 aPatil, Nita, A. R.1 aNiphadkar, Prashant1 aBokade, Vijay, V.1 aHaider, Ali1 aVinod, C., P.  uhttps://library.ncl.res.in/content/direct-conversion-methane-formic-acid-over-au-fe-nazsm-5-ambient-pressure-using-h2o2