Tailoring the multiphase flow pattern of gas and liquid through micro-packed bed of pillars

We describe the co-current flow pattern of gas and liquid through micro-fabricated beds of solid and pillars under variable (i) capillary number, (ii) contact angle or wettability and (iii) pillar arrangement, i.e. modifying the distance between pillars or their size and comparing regular with more chaotic systems. Laser-induced fluorescent...

Low-temperature atomic layer deposition delivers more active and stable Pt-based catalysts

We tailored the size distribution of Pt nanoparticles (NPs) on graphene nanoplatelets at a given metal loading by using low-temperature atomic layer deposition carried out in a fluidized bed reactor operated at atmospheric pressure. The Pt NPs deposited at low temperature (100 °C) after 10 cycles were more active and stable towards the...

Understanding and Controlling the Aggregative Growth of Platinum Nanoparticles in Atomic Layer Deposition: an Avenue to Size Selection

We present an atomistic understanding of the evolution of the size distribution with temperature and number of cycles in atomic layer deposition (ALD) of Pt nanoparticles (NPs). Atomistic modeling of our experiments teaches us that the NPs grow mostly via NP diffusion and coalescence rather than through single-atom processes such as precursor...

Inhibition of a Gold-Based Catalyst in Benzyl Alcohol Oxidation: Understanding and Remediation

Benzyl alcohol oxidation was carried out in toluene as solvent, in the presence of the potentially inhibiting oxidation products benzaldehyde and benzoic acid. Benzoic acid, or a product of benzoic acid, is identified to be the inhibiting species. The presence of a basic potassium salt (K2CO3 or KF) suppresses this inhibition, but promotes the...

Simultaneous hydrolysis and hydrogenation of cellobiose to sorbitol in molten salt hydrate media

The hydrolysis and hydrogenation of cellobiose (4-O-b-D-glucopyranosyl-D-glucose) in ZnCl2_4H2O solvent was studied to optimize the conditions for conversion of lignocellulose (the most abundant renewable resource) into sorbitol (D-glucitol). Water at neutral pH does not allow hydrolysis of cellobiose under the conditions of the experiments (up...

Sorbitol dehydration into isosorbide in a molten salt hydrate medium

The sorbitol conversion in a molten salt hydrate medium (ZnCl2; 70 wt% in water) was studied. Dehydration is the main reaction, initially 1,4- and 3,6-anhydrosorbitol are the main products that are subsequently converted into isosorbide; two other anhydrohexitols, (1,5- and 2,5-), formed are in less amounts and do not undergo further dehydration...

Photo-catalytic oxidation of cyclohexane over TiO2: A novel interpretation of temperature dependent performance

The rate of cyclohexane photo-catalytic oxidation to cyclohexanone over anatase TiO2 was studied at temperatures between 23 and 60ºC by in situ ATR-FTIR spectroscopy, and the kinetic parameters were estimated using a microkinetic model. At low temperatures, surface cyclohexanone formation is limited by cyclohexane adsorption due to unfavorable...