King Fahd University of Petroleum and Minerals

About: King Fahd University of Petroleum and Minerals is a education organization based out in Dhahran, Saudi Arabia. It is known for research contribution in the topics: Catalysis & Adsorption. The organization has 7603 authors who have published 24030 publications receiving 443803 citations. The organization is also known as: College of Petroleum and Minerals.

Highly efficient and selective oxidation of aromatic alcohols photocatalyzed by nanoporous hierarchical Pt/Bi2WO6 in organic solvent-free environment.

Abstract: Selective conversion of aromatic alcohols into corresponding aldehydes is important from energy and environmental stance. Here, we describe highly selective (>99%) and efficient conversion (>99%) of aromatic alcohols (e.g., 4-methoxybenzyl alcohol and 4-nitrobenzyl alcohol) into their corresponding aldehydes in the presence of Pt-modified nanoporous hierarchical Bi2WO6 spheres in water under simulated sunlight at ambient conditions. Overoxidation of p-anisaldehyde, formed during photooxidation process, was not observed until comprehensive alcohol oxidation was attained. Furthermore, the catalyst showed substantial oxidation under dark and course of conversion was different than that of under light. Dependency of alcohol oxidation on substrate concentration, photocatalyst amount, and Pt loading was studied. The effect of various radical scavengers was investigated, and the rate-determining step was elucidated. It has been envisaged that the reduction site of semiconductor photocatalysts plays more decisive...

A (rough) pathwise approach to a class of non-linear stochastic partial differential equations

Abstract: We consider non-linear parabolic evolution equations of the form ∂ t u = F ( t , x , D u , D 2 u ) , subject to noise of the form H ( x , D u ) ∘ d B where H is linear in Du and ∘ d B denotes the Stratonovich differential of a multi-dimensional Brownian motion. Motivated by the essentially pathwise results of [P.-L. Lions, P.E. Souganidis, Fully nonlinear stochastic partial differential equations, C. R. Acad. Sci. Paris Ser. I Math. 326 (9) (1998) 1085–1092] we propose the use of rough path analysis [T.J. Lyons, Differential equations driven by rough signals, Rev. Mat. Iberoamericana 14 (2) (1998) 215–310] in this context. Although the core arguments are entirely deterministic, a continuity theorem allows for various probabilistic applications (limit theorems, support, large deviations, …).

The role of diffusion in alkyl-benzenes catalytic cracking

Abstract: The present study reports the catalytic cracking of three hydrocarbon model compounds: cumene, 1,3-di- iso -propyl-benzene (1,3-DIPB) and 1,3,5-tri- iso -propyl-benzene (1,3,5-TIPB). Experiments were developed in a novel CREC Riser Simulator, a catalytic reactor that mimics the operating conditions of large-scale fluid catalytic cracking (FCC) units. Reaction testing involved different reaction times and temperatures, using Y-zeolites of different crystal sizes (0.4 and 0.9 μm). It was shown that cumene cracking and the cumene cracking products are unaffected by the zeolite crystal size. It was proven that 1,3-DIPB cracking; it remains unaltered with changes in crystal size with however, crystal dimensions affecting product selectivities. Regarding the 1,3,5-TIPB cracking, at 350–450 °C using the 0.4 μm Y-zeolites, higher 1,3,5-TIPB conversions were obtained. Differences on 1,3,5-TIPB conversions were however, less significant at 500–550 °C. It is postulated that the 1,3,5-TIPB conversion differences are caused by constrained diffusional transport in the Y-zeolite crystals and that the increase of temperature changes the catalytic cracking of 1,3,5-TIPB from the diffusionally controlled regime to the kinetically controlled regime.