Transitional analysis for multi-objective operative improvement of reformate quality and hydrogen production from a naphtha catalytic reforming process.

The hydrogen produced ( ) in the Catalytic Naphtha Reforming (CNR) is important in quantity and quality, for the feedback of the process and for supplying the hydrotreatment processes in current refineries. In this work it is presented a study by process simulation using ® for finding operative transitional modes that simultaneously improve quality of the reformate and hydrogen production of the CNR. The operative conditions that were studied correspond to the recirculation ratio of hydrogen/hydrocarbon ( ), with values between 2 and 6, and the temperature (), between 450 and 525 °C, in order to determining the best operative transitional route from the initial operative state to a local improved state, applying the method of superposition of response surfaces and criteria assessment of improvement in quality and quantity of hydrogen produced.

Hydrogenation/dehydrogenation of N-heterocycles catalyzed by ruthenium complexes based on multimodal proton-responsive CNN(H) pincer ligands.

Ru complexes based on lutidine-derived pincer CNN(H) ligands having secondary amine side donors are efficient precatalysts in the hydrogenation and dehydrogenation of N-heterocycles. Reaction of a Ru-CNN(H) complex with an excess of base produces the formation of a Ru(0) derivative, which is observed under catalytic conditions.

Hydroboration of carbon dioxide with catechol- and pinacolborane using an Ir-CNP* pincer complex. Water influence on the catalytic activity.

Iridium complexes based on deprotonated lutidine-derived CNP* pincers 2a/2b selectively catalyzed the hydroboration of CO2 under mild conditions (1-2 bar CO2, 30 °C) to methoxyborane using HBcat (TOF up to 56 h-1) and to the formate level with HBpin (TOF up to 1245 h-1). Interestingly, an intriguing, positive water effect on the reaction rates has been observed. NMR spectroscopy and ESI-MS analysis of the hydroboration reactions have shown the formation of ligand-protonated [Ir(CNP)(CO)(BR2)H][B(R2)2] (R2 = catecholate, pinacolate) derivatives under catalytic conditions.

Hydrogenation of an iridium-coordinated imidazol-2-ylidene ligand fragment.

An iridium complex featuring a metalated lutidine-derived CNP ligand reacts with KOtBu to yield a dimeric species with the two metal centers bound to the opposite ligands through the CHN arms. Furthermore, reaction with H2 in the presence of KOtBu of the same iridium derivative results in the hydrogenation of the -CH[double bond, length as m-dash]CH- imidazolylidene moiety of the complex. NMR spectroscopy monitoring of the latter reaction supports the initial formation of a dihydride iridium complex containing an imidazolylidene ligand fragment that is hydrogenated after prolonged reaction time.

Synthesis, structure and reactivity of Pd and Ir complexes based on new lutidine-derived NHC/phosphine mixed pincer ligands.

Coordination studies of new lutidine-derived hybrid NHC/phosphine ligands (CNP) to Pd and Ir have been performed. Treatment of the square-planar [Pd(CNP)Cl](AgCl) complex 2a with KHMDS produces the selective deprotonation at the CHP arm of the pincer to yield the pyridine-dearomatised complex 3a. A series of cationic [Ir(CNP)(cod)] complexes 4 has been prepared by reaction of the imidazolium salts 1 with Ir(acac)(cod).