On the enhanced catalytic activity of acid-treated, trimetallic Ni-Mo-W sulfides for quinoline hydrodenitrogenation

Deep Hydroisomerization of n-Hexadecane over NiWS/SAPO-11 Catalyst: Size Effect of the Support and Revelation of the Reaction Network

“…The results can be explained by the fact that with the decrease of particle size and crystal size of SAPO-11 molecular sieve, more and more “type I activity phase” converted to “type II activity phase” . More W atoms in the stacked “type II active phase” were located at the edge and corner sites of the active phase slabs, thus promoting the formation of more CUS sites. , The results in the literature showed that for a WS 2 -supported catalyst, there are obvious crystal defects in the position with hydrogenation activity. That is, W atoms with coordination unsaturation or W atoms at the edge or corner sites of WS 2 slabs easily lose S under heating conditions, and further theoretical calculation proved that W atoms at the corner sites have higher dehydrogenation/hydrogenation activity from the energy point of view. , Meanwhile, the NiWS active phase formed on the Brim surface of stacked WS 2 slabs was filled with WS 2 slabs between the active metals of this active phase and the catalyst support, while the interaction between the lower WS 2 slabs and the WS 2 slabs on the Brim surface was weak.…”

Catalytic Hydrodenitrogenation of Pyridine under Hydrothermal Conditions: A Comprehensive Study

“…Although piperidine was not to be found in this experiment, most likely because conversion of piperidine happened quickly and piperidine was consumed completely within 5 min, the hydrogenation route from pyridine to piperidine was widely reported by other research studies. − Therefore, we reasonably treat piperidine as an intermediate product in the model. Considering that hydrogenation of the nitrogen heterocyclic ring substance is a reversible reaction, − dehydrogenation of piperidine is also included in this network (eqs and ). Piperidine disappearance is involved in the following reactions: 1-piperidineethanol formation via the reaction between piperidine and formic acid (eq ), generation of 1-carbaldehyde piperidine by substitution of H on the N atom in pyridine with formic acid (eq ), formation of other piperidines via the derivative reaction (eq ), and 1-pentanol formation after ring rupture of piperidine (eq ), which further combines with piperidine and leads to formation of 1-pentyl piperidine (eq ). Next, both 1-piperidineethanol and 1-carbaldehyde piperidine can further undergo hydrogenation to form 1-ethyl piperidine (eq ) and 1-methyl piperidine (eq ), respectively. Considering that the hydrogenolysis of short-chain amines, alcohols, and hydrocarbons could occur under supercritical water conditions, − we lump those minor amines, alcohols, hydrocarbons, and gas products together as NH 2 -R, HO-R, C n H m , and GP, respectively, in the network.…”

“…Generally, path 1r has a direct or an indirect strong impact on each compound, which suggests that dehydrogenation from piperidine to pyridine cannot be negligible. Indeed, for HDN of nitrogen heterocyclic ring chemicals such as indole, quinoline, carbazole, and so forth, dehydrogenation was an indispensable and essential step during the whole reactions. For pyridine, except for path 1 and path 1r, other paths have little impact on it.…”

Cu Nanoclusters Anchored on the Metal–Organic Framework for the Hydrolysis of Ammonia Borane and the Reduction of Quinolines

“…On the other hand, hydrides of N-heteroarenes, which are obtained by the hydrogenation of aromatics, play an important role in the agrochemical and pharmaceutical industries. − Recently, a heterogeneous catalysis system applied in such processes undergo rapid development. − Notably, catalysts supported by noble metals, such as Ru, Rh, and Ir, provide a good catalytic platform and are successfully used in different aromatic hydrogenation reactions. − However, most of the studies on these processes concentrate on a simple model reaction. , The molecules often have more intricate structures in practical industry applications. Consequently, rational design and synthesis of supported metal catalysts with superb mass enrichment combined with excellent active sites are of equal importance for the catalytic reactions in pharmaceutical industries.…”

“…22−24 However, most of the studies on these processes concentrate on a simple model reaction. 25,26 The molecules often have more intricate structures in practical industry applications. Consequently, rational design and synthesis of supported metal catalysts with superb mass enrichment combined with excellent active sites are of equal importance for the catalytic reactions in pharmaceutical industries.…”