Promoting the production of industrially important aromatic chloroamines over transition-metal nitrides catalysts has emerged as a prominent theme in catalysis. This contribution provides an insight into the reduction mechanism of p-chloronitrobenzene (p-CNB) to p-chloroaniline (p-CAN) over the γ-Mo2N(111) surface by means of density functional theory calculations. The adsorption energies of various molecularly adsorbed modes of p-CNB were computed. Our findings display that, p-CNB prefers to be adsorbed over two distinct adsorption sites, namely, Mo-hollow face-centered cubic (fcc) and N-hollow hexagonal close-packed (hcp) sites with adsorption energies of −32.1 and −38.5 kcal/mol, respectively. We establish that the activation of nitro group proceeds through direct pathway along with formation of several reaction intermediates. Most of these intermediaries reside in a significant well-depth in reference to the entrance channel. Central to the constructed mechanism is H-transfer steps from fcc and hcp hollow sites to the NO/–NH groups through modest reaction barriers. Our computed rate constant for the conversion of p-CNB correlates very well with the experimental finding (0.018 versus 0.033 s–1 at ∼500 K). Plotted species profiles via a simplified kinetics model confirms the experimentally reported high selectivity toward the formation of p-CAN at relatively low temperatures. It is hoped that thermokinetics parameters and mechanistic pathways provided herein will afford a molecular level understanding for γ-Mo2N-mediated conversion of halogenated nitrobenzenes into their corresponding nitroanilines; a process that entails significant industrial applications.
Increasing demands on producing environmentally friendly products are becoming a driving force for designing highly active catalysts. Thus, surfaces that efficiently catalyse the nitrogen reduction reactions are greatly sought in moderating air-pollutant emissions. This contribution aims to computationally investigate the hydrodenitrogenation (HDN) networks of pyridine over the γ-Mo2N(111) surface using a density functional theory (DFT) approach. Various adsorption configurations have been considered for the molecularly adsorbed pyridine. Findings indicate that pyridine can be adsorbed via side-on and end-on modes in six geometries in which one adsorption site is revealed to have the lowest adsorption energy (
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The ground state charge, neutron and matter densities for two-neutron halo nuclei P
12
PBe
and P
14
PBe are calculated within a two- frequency shell model approach. In the description of
the halo nuclei it is important to take into account a model space for P
10
PBe and P
12
PBe different
from the two halo neutrons which have to be treated separately in order to explain their
properties. The structures of the halo P
12
PBe and P
14
PBe nuclei show that the dominant
configurations when the two halo neutrons distributed over the 1d shell orbits. Elastic
Coulomb scattering form factors of these two exotic nuclei are also studied through the
combination of the density distributions of
The restriction concept is a basic feature in the field of measure theory and has many important properties. This article introduces the notion of restriction of a non-empty class of subset of the power set on a nonempty subset of a universal set. Characterization and examples of the proposed concept are given, and several properties of restriction are investigated. Furthermore, the relation between the P*–field and the restriction of the P*–field is studied, explaining that the restriction of the P*–field is a P*–field too. In addition, it has been shown that the restriction of the P*–field is not necessarily contained in the P*–field, and the converse is true. We provide a necessary condition for the P*–field to obtain th
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The purpose of this paper is to study new types of open sets in bitopological spaces. We shall introduce the concepts of L- pre-open and L-semi-p-open sets
In this paper, we define a new type of pairwise separation axioms called pairwise semi-p- separation axioms in bitopological spaces, also we study some properties of these spaces and relationships of each one with the ordinary separation axioms in the bitopological spaces.
The significance of the work is to introduce the new class of open sets, which is said Ǥ- -open set with some of properties. Then clarify how to calculate the boundary area for these sets using the upper and lower approximation and obtain the best accuracy.
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In this paper we show that the function , () p fLI α ∈ ,0<p<1 where I=[-1,1] can be approximated by an algebraic polynomial with an error not exceeding , 1 ( , , ) kp ft n ϕ αω where
,
1 ( , , ) kp ft n ϕ αω is the Ditizian–Totik modules of smoothness of unbounded function in , () p LI