Pt-CeO2-based composites in environmental catalysis: A review

The Pt–CeO2-based composites have brought about a vivid research interest due to their use in advanced combustion engines, proton-exchange membrane fuel cells, etc. Complementing features of Pt and ceria particles cause numerous applications of such composites in environmental catalysis science and technology. The present review summarizes recent advances in Pt–CeO2 chemistry and discusses the following key aspects: (1) catalyst preparation, including Pt and Ce-MOF-derived precursors, and treatment methods, (2) Pt-related factors: size, including single-atom formulations, and state, (3) CeO2-related factors: morphology, surface defects, and derived features, (4) modification of catalyst composition, including the formation of bimetallic particles, (5) nature and structure of active sites, (6) features of metal–support interaction. The range of covered environmental catalytic applications includes oxidation processes (CO oxidation, VOCs abatement, soot oxidation, combustion of vehicle exhausts, etc.), reduction of nitroaromatics, CO2 utilization (dry reforming of alkanes, CO2 reduction, etc.), and photocatalytic reactions

Effect of Cu modifier on the performance of CrOx/Al2O3 catalysts for isobutane dehydrogenation

The peculiarities of active surface formation and the effect of Cu modifier on the performance of CrOx/Al2O3 catalysts in a fixed-bed isobutane dehydrogenation into isobutylene are considered using a series of model Cu-modified alumina supports (0.7–6.5% wt Cu) and CrOx catalysts on the basis thereof. The samples are characterized using a complex of physical-chemical methods, including low-temperature N2 adsorption, STA, XRF, XRD, UV–vis DR, Raman spectroscopy and H2-TPR. The modification of the alumina-chromia catalysts by a proper amount of copper is shown to enhance the catalyst activity. The catalyst with 2.6% wt Cu shows high conversion and selectivity towards isobutylene. The role of Cu modifier is connected with stabilizing of the active component mostly as monomeric and dimeric Cr(VI) species that can be reduced into the most active mononuclear and dimeric Cr3+ sites

Towards the understanding of promoting effects of Re, Cs and Cl promoters for silver catalysts of ethylene epoxidation: A computational study

Promoting effects of Cs, Re oxospecies, and Cl for silver catalysts of ethylene epoxidation are studied computationally using the DFT approach. The promoters are shown to enhance the extent of activation of initial substances, reaction intermediates, and products, while different combinations of promoters are favorable for different stages of the process. The synergistic effect of Cs, Re, and Cl is connected with the adjustment of the substrate location with respect to silver, thus, setting the favorable conditions for rapid transformation of ethylene into ethylene oxide. Re and Cl complement each other to balance and mitigate the effect of the Ag-bound Cs to alter the distribution of electronic density, tuning the electronic states of surface oxygen species by making it more electrophilic, and providing the substrate binding strength that ensures “optimal” substrate residence time and improves the catalyst performance in ethylene epoxidation

Synergistic effect of Cu and Zn modifiers on the activity of CrOx/Al2O3 catalysts in isobutane dehydrogenation

In this work, a series of Cu- and/or Zn-modified alumina-supported CrOx catalysts have been synthesized by wetness impregnation method and characterized using the combined techniques, including Raman spectroscopy, UV–vis DR, XRD, XRF, H2-TPR and low-temperature N2 sorption, to reveal the effect of the modifiers on the catalyst performance in a fixed-bed isobutane dehydrogenation into isobutylene. The Zn-based modifier is shown to decrease the reducibility of the supported chromium species and reduce the stability of the redox ones, which results in the decreased catalyst activity in isobutane dehydrogenation. The Cu-based modifier on the contrary facilitates the formation of high amount of redox chromium species that leads to the activity growth. The modification by both Cu- and Zn-based modifiers provides an enhanced catalyst performance caused by the synergistic effect of the modifiers and chromium species. The incorporation of the modifiers into alumina support facilitates the formation of the surface defective spinel phases that prevent the incorporation of chromium into the alumina surface and establish the conditions to form the high amount of the active redox chromium species

Optimization of Functional State of the Liver in Patients with Chd on the Background of Rosuvastatin Intake

In 2019, 18.6 million people died of cardiovascular diseases (CVDs) worldwide. Coronary heart disease (CHD) is the leading cause of death from CVDs. One of the main risk factors for atherosclerosis and its complications is hyperlipidemia. The progress achieved is due in no small part to the emergence of a new class of hypolipidemic drugs belonging to the group of statins - HMG-CoA reductase inhibitors. Statins are the most effective means of combating atherosclerosis, having proven the ability to slow or completely stop its progression. Usually, statin therapy is well tolerated, but side effects can develop, including elevation of hepatic enzymes - aminotransferases. In this regard, the administration of statins together with hepatoprotective drugs, such as milk thistle extract leads to a decrease in the side effects of hypolipidemic therapy in patients with CHD

The possibility of using remote sensing technology of lidar for monitoring ecosystem health by detecting habitat condition

Since the emergence of laser and henceforth laser remote sensing in the 1960's, lidar (light detecting and ranging) technology has became a significant tool for the detection of various phenomena like wind direction and intensity, atmospheric temperature, urban and rural topography, forest fires, ocean planktonic development, and detection of various constituants such as tropospheric aerosols, stratospheric ozone, trace chemicals and etc. In 2009, a homemade multiwavelength Raman aerosol lidar (named MRC K09) was designed, developed and installed in the Scientific and Technological Research Council of Turkey (TUBITAK) Marmara Research Center (MRC), and since 21 February 2011, it has been accepted to EARLINET (European Aerosol Research Lidar Network). Since 2009, aerosol spatio-temporal distribution and microphysical properties have been investigated in the extremely industrialized vicinity [1,2]. MRC K09 lidar uses a Quantel Brilliant B Nd:YAG laser (1064 nm) with the second and third optical harmonics at 532 and 355 nm, and a homemade Newtonian 40 cm aperture 120 cm focal length telescope. It has 7 channel spectrum analyzer detecting: parallel and perpendicular polarizations at 355 nm, elastic signals at 532 and 1064 nm, Raman signal of molecular nitrogen at 387 nm and Raman signal of water vapor at 408 nm (excited with 355 laser line), and Raman signal for molecular nitrogen at 608 nm (excited with 532 nm laser line). In Spring 2010, preliminary applications for the determination of forest tree species and of forest health in the Black Sea Area using an aeroborne lidar in collaboration with Bartin University, Bartin, Turkey have been made. In early 2011, a fluorescence module utilizing a Princeton Instruments PI-MAX3 1024x256 resolution CCD camera with a Princeton Instruments Acton SP 2500 0.500 m Imaging Triple Grating Monochromator/Spectograph was connected to the MRC K09 lidar system, and the first remote measurements of chlorophyll from different types of trees were made. Figure 1 demonstrates the results of these measurements, which must be considered as preliminary and in the future, the measurements can be carried out by the lidar mounted on an aircraft to cover large spatial areas. One of the most important reasons for biodiversity loss, habitat loss and fragmentation can be monitored in large areas by aeroborne lidars and therefore the extent of the situation can be accessed precisely, faster and more efficiently. This paper aims to give a brief overview to show the possibility of detecting the detailed situations of the habitats on terrain surfaces using lidar technology by summarizing the successful examples which have been realized thus far in different types of ecosystems like savannas, forest and grasslands. © 2013 SPIE

Optimization of Functional State of the Liver in Patients with Chd on the Background of Rosuvastatin Intake

In 2019, 18.6 million people died of cardiovascular diseases (CVDs) worldwide. Coronary heart disease (CHD) is the leading cause of death from CVDs. One of the main risk factors for atherosclerosis and its complications is hyperlipidemia. The progress achieved is due in no small part to the emergence of a new class of hypolipidemic drugs belonging to the group of statins - HMG-CoA reductase inhibitors. Statins are the most effective means of combating atherosclerosis, having proven the ability to slow or completely stop its progression. Usually, statin therapy is well tolerated, but side effects can develop, including elevation of hepatic enzymes - aminotransferases. In this regard, the administration of statins together with hepatoprotective drugs, such as milk thistle extract leads to a decrease in the side effects of hypolipidemic therapy in patients with CHD