Abhijit Shrotri

Cellulosic biomass is the largest source of renewable organic carbon on our planet. Cellulose accounts for 40-50 wt % of this lignocellulose, and it is a feedstock for industrially important chemicals and fuels. The first step in cellulose conversion involves its depolymerization to glucose or to its hydrogenated product sorbitol. The hydrolysis of cellulose to glucose by homogeneous mineral acids was the subject of research for almost a century. However, homogeneous acids have significant drawb

Controlling the selectivity of products among CO, methane, and methanol is a challenge in CO2 hydrogenation. Catalysts with oxygen vacancies are helpful for CO2 activation, but they exhibit poor CO selectivity as intermediates stabilized over oxygen vacancies undergo deep hydrogenation to methanol and methane. Here, we report the synthesis of a catalyst with isolated Co atoms in ZrO2 that exhibits oxygen vacant sites near Co atoms owing to charge imbalance between cations. The resulting catalyti

Water soluble oligomers of cellulose were produced by milling acidulated microcrystalline cellulose. Acids with low pKa were found to be more effective for the treatment. The yield of water soluble fraction was proportional to the increasing severity of milling or the acid amount. Soluble oligomers were found to have an average degree of polymerisation of ∼7 monomer units. High resolution NMR spectroscopy was used to determine the chemical structures of soluble oligomers. It was found that branc

Atomically dispersed Rh promoted the activity of In₂O₃ for methanol formation from CO₂, inducing strong CO₂ adsorption and enhanced formate formation.

Sorbitol is one of the key platform chemicals that can be applied to several industrial applications, including bio-fuels and hydrogen production. Presently there is no commercial heterogeneous catalytic process to produce sorbitol from cellulose due to the low yield and high cost of noble metals required for the conversion. In this paper we describe an aqueous phase hydrolysis–hydrogenation process to convert cellulose to sorbitol using a cheap Ni based catalyst. Monometallic Ni catalysts showe

Oxygenated carbon catalyzes the hydrolysis of cellulose present in lignocellulosic biomass by utilizing the weakly acidic functional groups on its surface. Here we report the synthesis of a biomimetic carbon catalyst by simple and economical air-oxidation of a commercially available activated carbon. Air- oxidation at 450-500 °C introduced 2000-2400 μmol g(-1) of oxygenated functional groups on the material with minor changes in the textural properties. Selectivity towards the formation of carbo

Furfural was synthesized from hexose sugars instead of 5-HMF by using polar aprotic solvents with very low basicity.

Selective production of succinic acid from furfural with H2O2 over Sn-Beta, a pure Lewis acid catalyst, is reported. Under optimized reaction conditions, 53% yield of succinic acid was obtained, and the catalyst was recyclable. 2(3H)-Furanone was detected as an intermediate using 1H nuclear magnetic resonance (NMR), HH correlation NMR spectroscopy, liquid chromatography–mass spectrometry (MS) and gas chromatography–MS. Kinetic modeling revealed that Baeyer–Villiger oxidation of furfural to 2(3H)

Abstract Ru supported on activated carbon was found to be active for the transfer hydrogenation of cellulose oligomers, which were produced by the milling of acidulated microcrystalline cellulose. A C 6 sugar alcohol yield of 85 % was obtained in less than 1 h reaction time in a batch reactor. Optimum reaction conditions for transfer hydrogenation were determined as 180 °C and a pH above 2.2 using glucose as a substrate. Use of deuterium as a marker established that direct transfer of hydride sp

Abstract A carbon catalyst containing a high density of carboxyl groups was prepared by solvent‐free mechanochemical oxidation of activated carbon by using persulfate salts as the oxidant. The mechanochemical oxidation preferentially oxidized the carbon to introduce carboxyl groups without incorporation of sulfonated groups. The material exhibited hydrophilic behavior and was easily dispersed in water. Upon mix‐milling, the oxidized carbon showed good catalytic activity for the hydrolysis of cel

During the hydrogenation of CO₂ to methanol over mixed-oxide catalysts, the strong adsorption of CO₂ and formate poses a barrier for H₂ dissociation, limiting methanol selectivity and productivity. Here we show that by using Co-containing dual-atom oxide catalysts, the poisoning effect can be countered by separating the site for H₂ dissociation and the adsorption of intermediates. We synthesized a Co- and In-doped ZrO₂ catalyst (Co-In-ZrO<su

Larger cello-oligosaccharides undergo faster hydrolysis over carbon catalysts. This is attributed to reduction in activation energy caused by conformational change in the structure of oligosaccharides as they adsorb within the micropores of carbon.