Проведено DFT-моделирование адсорбции водорода на наночастицах Ni, Pt и Pd на графите. Рассчитывались энергии связи 13-атомных металлических кластеров на графите с различными дефектами с атомарным водородом. Исследовалось изменение плотности состояний атомов металлов при взаимодействии с этим адатомом. Платиновый кластер имеет наиболее активную вершину. Для палладиевого и никелевого кластеров вся поверхность реакционноспособна. Все приведенные выше выводы согласуются с результатами экспериментальных исследований. DFT modeling of hydrogen adsorption on Ni, Pt and Pd nanoparticles on graphite has been performed. The binding energies of 13-atomic metal clusters on graphite with various defects with atomic hydrogen were calculated. The change in the density of states of metal atoms during interaction with this atom was studied. The platinum and nickel clusters has the most active top. For a palladium and nickel clusters, the entire surface is reactive. All the above conclusions are consistent with the results of experimental studies.

Проведено квантово-химическое моделирование адсорбции водорода на золотых и медных наночастицах на графите в рамках теории функционала плотности (DFT), в результате которого рассчитаны энергии связи металлических кластеров на графите с различными дефектами с атомарным водородом и изучено изменение плотности состояний атомов металлов при взаимодействии с этим адатомом. Для золота было выявлено большее уменьшение плотности состояний на границе металл-графит, для меди тенденций обнаружено не было. Все приведенные выше выводы согласуются с результатами экспериментальных исследований. Quantum-chemical modeling of hydrogen adsorption on gold and copper nanoparticles on graphite was conducted within the framework of density functional theory (DFT). As a result, bonding energies of atomic hydrogen with metal clusters on graphite with various defects were calculated, and the change in the density of states of metal atoms during interaction with this adatom was studied. For gold, a greater decrease in the density of states at the metal-graphite interface was observed, while no trends were found for copper. All the above conclusions are consistent with the results of experimental studies.

С помощью моделирования в рамках теории функционала плотности адсорбции атомарных кислорода и водорода на поверхности наночастиц палладия на подложках графита с различными дефектами были рассчитаны энергии связи адатомов и изменения плотности состояний атомов металла при взаимодействии с адатомами. Установлено, что энергетическая стабильность адсорбции кислорода и водорода не зависит от места адсорбции адатома на поверхности наночастицы (интерфейс или вершина), что согласуется с результатами СТМ/СТС-экспериментов.

Density functional theory (DFT) modeling of the adsorption of atomic oxygen and hydrogen on the surface of palladium nanoparticles on graphite substrates with various defects is used to calculate the binding energies of adatoms and changes in the density of states of metal atoms upon interaction with adatoms. It is established that the adsorption of oxygen and hydrogen does not have more energetically favorable or stable adsorption sites on the surface of the nanoparticle, such as the interface with the substrate or the top, which is consistent with the results of the scanning tunneling microscopy and spectroscopy (STM/STS) experiments.

The quantum-chemical modeling of copper nanoparticles on graphite substrates with various defects shows a stronger decrease in the density of the states of copper atoms during hydrogen adsorption near the interface compared to similar adsorption far from it. It is also found that, in general, the effect of the substrate on the atomic and electronic structures of the copper nanoscale system is less pronounced than that of the gold nanoscale system.

Using the density functional theory (DFT) simulation of the adsorption of atomic oxygen and hydrogen on the surface of nickel and platinum nanoparticles on graphite substrates with various defects, we calculate the binding energies of adatoms and changes in the density of states of metal atoms upon interaction with adatoms. It is found that the density of states decreases more when oxygen is adsorbed at the top of a metal cluster than when oxygen is adsorbed at the interface between the metal cluster and the graphite substrate. For hydrogen adsorption, no such dependences are found. It is shown that the effect of monatomic defects of the substrate is insignificant in the case of adsorption of both types of adatoms.

Using the method of quantum-chemical modeling of a system of gold nanoparticles on a graphite substrate with various defects, a decrease in the density of states of gold atoms during the adsorption of hydrogen near the interface is shown. Substrate defects, such as vacancies and cutoffs of the graphene plane, contribute to a decrease in the density of states during the adsorption of hydrogen atoms.

This paper presents the results of quantum chemical modeling of hydrogen atom adsorption on AuNi, AuCu, and CuNi bimetallic nanoparticles. It is established that changes in the electronic structure of these clusters depend both on the transformation of the atomic structure of the cluster and on charge transfer. The effect of charge transfer manifests itself most noticeably in clusters consisting of atoms with slightly different lattice constants Cu and Ni. With strong differences in this parameter, changes in adsorption properties will be determined to a greater extent by the transformation of the atomic structure.

Гидрирование наночастиц может являться ключевой стадией обезвреживания опасных химических веществ, в том числе монооксида углерода. В работе представлены результаты квантово-химического моделирования процесса гидрирования золотых и биметаллических золото-медных наночастиц на примере их взаимодействия с атомарным водородом при варьировании элементного состава кластера и мест адсорбции атома водорода. Предсказаны эффекты взаимодействия кластеров Au и Cu с атомарным водородом, которые были подтверждены результатами исследования адсорбционных свойств указанных наночастиц с помощью методик сканирующей туннельной микроскопии и спектроскопии. Показано, что водород устойчиво хемосорбируется на наночастицах. По данным DFT-моделирования адсорбции водорода установлено, что изменения электронной структуры биметаллической наносистемы могут способствовать повышению химической активности, например, в реакциях нанокатализа. Hydrogenation of nanoparticles is known to be a key step in deactivation of hazardous chemicals, including carbon monoxide. The results of quantum-chemical modeling the process of hydrogenation of gold and bimetallic gold-copper nanoparticles are presented using an example of their interaction with atomic hydrogen under varying parameters of elemental composition of clusters and adsorption sites of hydrogen atom. The effects of the interaction of Au and Cu clusters with atomic hydrogen have been predicted and further confirmed by the results of studying the adsorption properties of the nanoparticles using scanning tunneling microscopy and Auger electron spectroscopy techniques. It has been shown that hydrogen is stably chemisorbed on nanoparticles. According to the DFT simulation analysis of hydrogen adsorption, the changes in electronic structure of the bimetallic nanosystem are found to contribute in increase of the system’s chemical activity which can be useful, for example, in nanocatalyzed reactions.

Investigation data presented revealed association between pulmonary hypertension and the stage of chronic renal disease. It was shown that development of pulmonary hypertension was noted at the earliest stages of the chronic renal disease (when glomerular filtration rate decreased to < 80 ml/min) and the rate of hypertension development increased with the progression of the disease.