Process for increasingly producing D-Lactide and meso lactide by depolymerizing by back biting polylactide (PLA) said process which comprises: (i) Depolymerizing polylactide into its corresponding dimeric cyclic esters by heating the polylactide in the presence of a catalyst system comprising a catalyst and a co-catalyst in a reaction zone at temperature and pressure at which the polylactide is molten; (ii) Forming a vapor product stream from the reaction zone; (iii) Removing the vapor product stream and optionally condense it; (iv) Recovering, either together or separately meso-lactide, D-lactide and L-lactide.

A process for producing polymer-supported metal nanoparticles involves confinement of metal nanoparticles in polymeric nanotubes or nanosheets in an aqueous environment using hydrophobic reactants. Metal nanoparticles supported in the polymeric nanotubes or nanosheets are substantially monodisperse and have an average particle size of 4 nm or less. The polymer-supported metal nanoparticles are useful in fuel cells, sensors, bioanalysis, biological labeling or semi-conductors, especially as catalysts.

This disclosure features a urea conversion catalyst located within a urea decomposition reactor (e.g., a urea decomposition pipe) of a diesel exhaust aftertreatment system. The urea conversion catalyst includes a refractory metal oxide and a cationic dopant. The urea conversion catalyst can decrease the temperature at which urea converts to ammonia, can increase the urea conversion yield, and can decrease the likelihood of incomplete urea conversion.

Disclosed herein are processes, systems, and reaction systems for the oligomerization of ethylene to form an ethylene oligomer product in a reaction zone using a catalyst system having i) a chromium component comprising a heteroatomic ligand chromium compound complex of the type disclosed herein, and ii) an aluminoxane. A C.sub.3+ olefin can be present in the reaction zone for a period of time, where the C.sub.3+ olefin is not an ethylene oligomer formed in-situ within the reaction zone.

The present invention relates to a ligand compound, a catalyst system for olefin oligomerization, and a method for olefin oligomerization using the same. The present ligand compound is a compound having a certain new structure and enables provision of a catalyst system for olefin oligomerization that can oligomerize ethylene with higher catalytic activity.

A carbon structure comprising a mixture and a polymer. The mixture has a base carbon and a catalytic carbon. The polymer has a first binder with a median diameter of less than 10 microns and a second binder with a median diameter between 10 and 70 microns.

A catalytic membrane composite that includes porous supported catalyst particles durably enmeshed in a porous fibrillated polymer membrane is provided. The porous fibrillated polymer membrane may be manipulated to take the form of a tube, disc, or diced tape and used in multiphase reaction systems. The supported catalyst particles are composed of at least one finely divided metal catalyst dispersed on a porous support substrate. High catalytic activity is gained by the effective fine dispersion of the finely divided metal catalyst such that the metal catalyst covers the support substrate and/or is interspersed in the pores of the support substrate. In some embodiments, the catalytic membrane composite may be introduced to a stirred tank autoclave reactor system, a continuous flow reactor system, or a Parr Shaker reaction system and used to effect the catalytic reaction.

A process for the synthesis of Dapsone and intermediates thereof are described.

Provided herein are diaryl and arylalkyl phosphonates, useful as intermediates in, for example, the synthesis of leukocyte elastase inhibitors, potassium channel modulators, chemiluminescence materials, and flame retardants, and methods for making same. Also provided are N-heterocyclic phosphorodiamidic acids (NHPAs) useful in reactions such as, for example, in the preparation of diaryl and arylalkyl phosphonates. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.

Embodiments are directed to adamantane-intercalated layered double-hydroxide (LDH) particles and the methods of producing adamantane-intercalated LDH particles. The method comprises adding to an aqueous solution a first precursor and a second precursor to form an initial mixture, where the first precursor is Al(OH).sub.3 or Al.sub.2O.sub.3, the second precursor is a hydroxide M(OH).sub.2 or an oxide MO, where M is a metal of oxidation state +2; and the initial mixture has a M/Al molar ratio of from 1 to 5. The method also comprises adding to the initial mixture an amount of adamantane to form a reaction mixture having an Al/adamantane molar ratio of from 0.5 to 2; and heating the reaction mixture to produce adamantane-intercalated LDH particles, where the adamantane-intercalated LDH particles have aspect ratios greater than 100.