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A fundamental understanding of the active sites in working catalysts can guide the rational design of new catalysts with improved performances. In this work, we have followed the evolution of homogeneous and heterogeneous Pd catalysts under the reaction conditions for aerobic oxidative coupling of toluene for the production of 4,4′-bitolyl. We have found that subnanometer Pd clusters made with a few Pd atoms are the working active sites in both homogeneous and heterogeneous catalytic systems. Moreover, water can promote the activity of Pd clusters by nearly one-order magnitude for oxidative coupling reaction by facilitating the activation of O2. These new insights lead to the preparation of a catalyst made with Pd clusters supported on a two-dimensional zeolite, which expands the scope of the oxidative coupling of aromatics to larger substrates. A fundamental understanding of the active sites in working catalysts can guide the rational design of new catalysts with improved performances. Here, regioselective oxidative coupling of toluene to 4,4'-bitolyl is achieved with zeolite-encapsulated Pd catalysts under acid-free conditions, and the active sites are identified to be the subnanometer Pd clusters confined in the channels of Beta zeolite. [ABSTRACT FROM AUTHOR]

It was established that the surface functionality of nanoglobular carbon (NGC) can be effectively altered by treatment at temperatures of 573 – 1173 K in an inert atmosphere, without affecting the structure and morphology of the material as a whole. The destruction and loss of surface oxygen groups occurs as a result of this treatment, which is accompanied by a decrease in the concentration of paramagnetic centers. At a temperature of 1173 K, a restructuring and "smoothing" of the carbon surface apparently takes place, which is expressed by annealing of defects (sources of EPR signal). It was found that changes in the surface functionality of NGC affect the reducibility of supported palladium precursor and the formation of palladium nanoparticles, without causing changes in palladium dispersion state. The study of the obtained Pd/NGC catalysts in the practically important hydrogenation of 4-nitrobenzoic acid ethyl ester and furfural showed that thermal pre-treatment of the support affects the catalytic performance in these reactions. It is important that varying temperature of such pre-treatment over a fairly wide range, which has a significant impact on the functionality of the support surface, leads to only relatively small changes in the activity and selectivity of the resulting catalysts. In this regard, thermal pre-treatment of carbon support should be considered as an approach to fine tune the performance of carbon-supported palladium catalysts. [ABSTRACT FROM AUTHOR]

Polydopamine (PDA)-coated Zn–Al-layered double hydroxide (Zn-Al LDH@PDA) have been synthesized through a simple and green procedure. In the present study, for the first time, Pd nanoparticles were successfully deposited using Zn-Al LDH@PDA as an efficient reducing biotemplate and stabilizing support. In this protocol, Pd ions were adsorbed on surfaces of Zn-Al LDH@PDA through immersion of the Zn-Al LDH@PDA nanocomposite into a palladium plating bath. Next, they were reduced in situ to palladium nanoparticles using PDA's N-containing groups and reducing ability. The structure, morphology and physicochemical properties of the synthesized nanoparticles were characterized by different analytical techniques such as energy-dispersive X-ray spectroscopy (EDS), field emission scanning electron microscope (FE-SEM), Fourier-transform infrared spectroscopy (FT-IR) spectroscopy, transmission electron microscopy (TEM), high resolution transmission electron microscopy (HR-TEM), fast Fourier transform (FFT),inductively coupled plasma (ICP), nitrogen physical adsorption (BET), elemental mapping and X-ray Diffraction (XRD).The catalytic potential of Zn-Al LDH@PDA/Pd NPs nanocatalyst was then evaluated in the Suzuki–Miyaura coupling reactions. These tests indicated that Zn-Al LDH@PDA/Pd NPs nanocatalyst is tolerant against various functional groups, and the desired biphenyl products were acquired with good to high yields within short times. The Zn-Al LDH@PDA/Pd NPs nanocatalyst was isolated by centrifuge and it was stable enough to be reused for 7 consecutive times without considerable loss in activity. [ABSTRACT FROM AUTHOR]

Spent Pd-Al2O3 catalyst was recovered by the metal smelting method. Cu and Fe were used as collector metals, and the capture process, smelting slag, and Pd-bearing alloy were comprehensively compared. The process condition results show that although the recovery rate of palladium of both capture processes is > 99%, the collection time using Fe smelting method is longer than that using Cu collection. The Si and P contents in Pd-bearing alloy under 1550°C obtained by Fe collection are obviously higher than those by Cu collection, which causes the difficulty in separation of Pd from impurities. The cost of Fe smelting process is much lower than that of Cu smelting process, while the metal Cu alloy can be further reused through subsequent electrolysis separation. Therefore, Cu collection is suggested to be a better collection metal due to the shorter smelting time, possible lower impurity content under higher temperature and more favorable subsequent treatment process. [ABSTRACT FROM AUTHOR]

Heavy metal levels have steadily risen over the past century due to the presence of human activity and are hazardous to human health and the environment. Regarding the health of humans and the environment, palladium (Pd) is among the most hazardous and toxic heavy metals. It is listed as a priority contaminant by the Agency for Toxic Substances and Disease Registry (ATSDR). As a result, eliminating pollution and tracking changes in Pd contamination in the air are the top research priorities. This study will be conducted on trees grown in Düzce, the fifth dirtiest city on the European continent, to identify appropriate species that may be utilized for tracking and mitigating Pd pollution in the air. Samples from Cupressus arizonica, Pinus pinaster, Cedrus atlantica, Pseudotsuga menziesii, and Picea orientalis will all be analyzed as part of the study, and the variations in Pd content according to species, organ, and direction will be assessed. The goal is to ascertain which biomonitors are best suited for tracking and mitigating lead contamination in the atmosphere. The study consistently found Pd contents in woods with different directions that developed within the same period. However, when the species were compared, notable differences were detected between the Pd levels formed in different directions in the same period for each species and the wood formed in the same direction in other periods. This variation suggests that Pd transfer in wood is restricted in all tested species. Consequently, every species performs as a reliable biomonitor for tracking Pd contamination. [ABSTRACT FROM AUTHOR]

Schiff base complexes play a crucial role in bioinorganic chemistry. A novel curcumin/phenylalanine tridentate Schiff base ligand and its palladium (II) complex were synthesized so that they were stable in aqueous buffer. The structure of the complex was investigated using a variety of methods, including DFT, NBO analysis, FMOs, and MESP. The interaction of the complex with a plasmid (pUC19) and CT-DNA was studied. The anticancer, antibacterial, and antioxidant activities of the complex were examined. The statistical analysis of the MTT assay was compared using the 1-way ANOVA and Tukey test. Results showed that the complexes were stable in aqueous buffer, pH 8. The extrinsic fluorescence emission of the plasmid and CT-DNA was quenched while interacting with the complex. The complex had an IC50 of 72.47 µM against MCF-7 cells. The ANOVA and Tukey analysis of MTT data demonstrated a statistically significant difference between groups (P < 0.0001). The minimum inhibitory concentrations (MIC) of the complex for E. coli and S. aureus were 300 and 200 µg/mL, with 96.3 and 95.2% biofilm growth inhibition at 250 µg/mL, respectively. The sample concentrations contributing to 50% radical inhibition in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) test for curcumin, ligand, and palladium (II) complex were 33.62, 21.27, and 51.26 µM, respectively. The results suggest that the complex interaction with DNA is one of the potential mechanisms for eliminating cancer cells and bacteria in the planktonic and biofilm. On the other hand, while stability in an aqueous buffer at pH 8 increases, the modified curcumin antioxidant effect decreases. [ABSTRACT FROM AUTHOR]

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Nitroaromatic compounds represent a class of highly toxic pollutants discharged into aquatic environments by various industrial activities, posing significant threats to ecological integrity and human health due to their persistent and hazardous nature. In this study, Pd-doped ZnO nanoparticles were investigated as a potential solution for the degradation of nitro organics, offering heightened photocatalytic efficacy and prolonged stability. The synthesis of Pd-doped ZnO NPs was achieved via the hydrothermal method, with subsequent analysis through XRD spectra and XPS confirming successful Pd doping within the ZnO matrix. Characterization through FESEM and HRTEM unveiled the heterogeneous morphologies of both undoped and Pd-doped ZnO nanoparticles. Additionally, UV–vis and PL spectroscopy provided insights into the optical properties, chemical bonding, and defect structures of the synthesized Pd-doped ZnO NPs. Pd doping induces a redshift in ZnO's absorption spectra, reducing the bandgap from 3.12 to 2.94 eV as Pd concentration rises from 0 to 0.2 wt.%. The photocatalytic degradation, following pseudo-first-order kinetics, achieved 90% nitrobenzene abatement (200 µg/L, pH 7) under visible light within 320 min with a catalyst loading of 16 µg/mL. The photocatalytic efficacy of 0.08 wt% Pd-doped ZnO (k = 0.058 min⁻1) exhibited a 25-fold enhancement compared to bare ZnO (k = 3.1 × 10–4 min-1). Subsequent quenching and ESR experiments identified hydroxyl radicals (OH•) as the predominant active species in the degradation mechanism. Mass spectrometry analysis unveiled potential breakdown intermediates, illuminating a plausible degradation pathway. The investigated Pd-doped ZnO nanoparticles demonstrated reusability for up to five successive treatment cycles, offering a sustainable solution to nitro organics contamination challenges. [ABSTRACT FROM AUTHOR]

The excellent physical and chemical properties of palladium(Pd) have made its application and demand increase gradually. Therefore, it is important to develop a new material to efficiently separate and purify palladium from secondary sources to ensure its supply. In this work, a thermosensitive palladium smart imprinted polymer(Pd-T-SIP) was synthesized, which could achieve the efficient separation and purification of Pd. The microstructure and morphology of Pd-T-SIP were characterized. The experimental results showed that the Pd-T-SIP showed the maximum adsorption amount(Q) of 0.1022 mmol/g for Pd(IV), the desorption rate(D) was 83.09%, and it had good reusability. Theoretical studies showed that the adsorption process of Pd-T-SIP was suitable to be described by quasi-first-order model and Langmuir model, which indicated that the adsorption of Pd-T-SIP was monolayer adsorption. Finally, Pd-T-SIP was applied to the platinum group catalyst leach solution, and it could be found that its adsorption/desorption effect was more excellent, with its adsorption amount reaching 0.1558 mmol/L, desorption rate reaching 77.14%, and the palladium purity after one adsorption/desorption cycle increased from 13.75% to 30.62%, and the purity of platinum group metals increased from 40.29% to 73.56% after one adsorption/desorption cycle. [ABSTRACT FROM AUTHOR]

The content and distribution of precious metals in fine-grained bottom sediments, accumulated in the technogenic period (last decades) in the southwestern part of the Chukchi Sea, have been studied. The ubiquitous or local enrichment of the sediments with silver, gold, platinum, and palladium according to the average for the Earth's crust, as well as their enrichment with gold and palladium relative to pre-technogenic (Late Holocene) deposits, was shown. Differences in the conditions of the accumulation of precious metals in the Late Holocene and modern sediments were shown. Sources of input were determined, and the possibility of technogenic enrichment of the sources was proved by the methods of multicomponent statistical analysis of the total chemical composition of the sediments. [ABSTRACT FROM AUTHOR]

In the Kumada reaction, commercially accessible nickel catalysts facilitate the synthesis of 2-arylbenzothiazoles from various aryllithium compounds and 2-chlorobenzothiazole. This catalytic process is effective irrespective of the presence of electron-withdrawing or electron-donating groups on the benzene ring of aryllithium. Among these zero-valent, divalent nickel, and divalent nickel complexes, divalent nickel complexes have the best catalytic effect. NiCl2(PCy3)2 (Cy = cyclohexyl) has the best catalytic performance. The highest yield of 2-C6H4benzopyrazole from C6H4Li and 2-chlorobenzopyrazole was 92.1% with the use of an NiCl2(PCy3)2 catalyst. this method eliminates the need for expensive palladium reagents and nickel complexes that require synthesis. [ABSTRACT FROM AUTHOR]

Three new palladium(II)-iminophosphine complexes, [Pd(L1)(Cl)2] C1, [Pd(L2)(Cl)2] C2 and [Pd(L3)(Cl)2] C3 have been synthesized and successfully characterized by using 1H-NMR, 13C-NMR, 31P-NMR, UV–Vis, FT-IR and magnetic susceptibility techniques. Catalytic activities of complexes towards Suzuki–Miyaura C–C coupling reactions between phenylboronic acid and several aryl halides were investigated under several reaction conditions (solvent, temperature, base, reaction time, and type of substrate). Under optimum conditions, achieving high yields of up to 99% was possible. When 1-bromo-4-nitrobenzene was used for complex C1, bromobenzene for complex C2, and bromobenzene for complex C3, product yields of 99, 99, and 98% were achieved, respectively. Three new palladium complexes bearing iminophosphine ligands was synthesized and successfully characterized. Catalytic activities of the synthesized complexes were investigated on Suzuki–Myaura type coupling reaction between phenylboronic acid and several aryl halides. All complexes exhibited good catalytic activities on C–C coupling reactions up to 99% product formations under mild conditions. [ABSTRACT FROM AUTHOR]

Semihydrogenation of trace acetylene in an ethylene gas stream is a vital step for the industrial production of polyethylene, in which Pd single-site catalysts (SSCs) have great potential. Herein, two Pd SSCs with different coordination structures are prepared on hierarchical nitrogen-doped carbon nanocages (hNCNC) by regulating the nitrogen species with or without using dicyandiamide. With using dicyandiamide, the obtained Pd1-Ndicy/hNCNC SSC features the coordinated Pd by two pyridinic N and two pyrrolic N (PdN2pyN2pr). Without using dicyandiamide, the obtained Pd1/hNCNC SSC features the coordinated Pd by pyridinic N and C (PdNxpyC4−x, x = 1–4). The former exhibits an 18-fold increase in catalytic activity compared to the latter. Theoretical results reveal the abundant unoccupied orbital states above the Fermi level of PdN2pyN2pr moiety, which can facilitate the activation of substrate molecules and dynamics of acetylene hydrogenation as supported by the combined theoretical and experimental results. In addition, the PdN2pyN2pr moiety presents a favorable desorption of ethylene. Consequently, the Pd1-Ndicy/hNCNC SSC exhibits high C2H2 conversion (99%) and C2H4 selectivity (87%) at 160 °C. This study demonstrates the impact of Pd single-site coordination structure on catalytic performance, which is significant for the rational design of advanced Pd SSCs on carbon-based supports. [ABSTRACT FROM AUTHOR]

The review discusses the latest advances in the study of heterogeneous metal-containing catalysts for the production of an environmentally friendly energy carrier—hydrogen—by the dehydrogenation of formic acid (FA), which is an available and low-toxic substance. Although the activity of homogeneous catalysts in the FA dehydrogenation reaction is higher than that of heterogeneous catalysts, the use of the latter makes it possible to simplify the technology and improve the environmental safety of hydrogen production from FA. An increase in the efficiency of heterogeneous FA dehydrogenation catalysts based on noble metals (Pd, Au, Ag) is achieved by developing novel methods for synthesizing monometallic, bimetallic, and trimetallic nanoparticles on various supports. The review compares the efficiency of various heterogeneous nanocatalysts in the FA dehydrogenation reaction and discusses various factors (metal nature, nanoperticle size and composition, support nature) that affect the activity and hydrogen selectivity of the catalysts. A significant increase in activity in the FA dehydrogenation reaction is achieved by intensifying the interaction of metal nanoparticles with the surface of a chemically modified support, which contributes to a decrease in the size of nanoparticles, an increase in the uniformity of their distribution on the support, and a change in the electronic state of the metal. Advances in the development of industrial heterogeneous catalysts for the production of pure hydrogen from FA will provide a significant contribution to the development of hydrogen power engineering. [ABSTRACT FROM AUTHOR]

Features of the catalytic action of Pd–Ag, Pd–Cu, Pd–Au, Pd–Ga, and Pd–Zn bimetallic systems on the acetylene conversion to ethylene are discussed taking into account two factors that determine the effect of the second metal on palladium, namely, the "ensemble effect" (geometric effect) and the "ligand effect" (electronic effect). The relationship between the calculated thermodynamic and kinetic parameters of the adsorption interaction of major reaction medium components and intermediates with the catalyst surface, the structure of active ensembles, and characteristics determined in tests, such as the structural parameters of bimetallic phases, the electronic state of their components, and catalytic properties, is shown. Some examples are given to show that the modifier atoms can be incorporated into active ensembles and the sites formed by the modifier atoms can be involved in the catalysis of individual elementary steps. [ABSTRACT FROM AUTHOR]

Mixed-ligand complexes of Pd(II) and Pt(II) with 2H-benzo[e][1,3] oxazine-2,4(3H)-dione (HBzoxe), tertiary phosphines (dppe, dppp, dppf and Ph3P), 2,2′-bipyridine (Bipy) and 1,10-phenanthroline (Phen) have been synthesized and characterized by molar conductance measurements, elemental analysis, IR and NMR (1H, 13C and 31P) spectroscopy. In addition, the antimicrobial activity assay studies. The results showed that the HBzoxe ligand behaves as a bidentate chelation ligand through the O and N atoms in [M(Bzoxe)2] {MII = Pd(1) and Pt(2)} complexes, whereas it acts as monodentate ligand through the oxygen atom in complexes (3–14) to afford a square planner geometry around Pd(II) and Pt(II) for all of the complexes. All of the complexes were moderately active on all the bacteria tested (Staphylococcus aureus and Escherichia coli). Hirshfeld surface analysis was carried out to investigate the cooperative non-covalent supramolecular interactions within the various complexes. [ABSTRACT FROM AUTHOR]

The combination of common semiconductors with porous materials has the potential to augment the splitting of electrons and holes, hence increasing the efficiency of gases-sensitive. This study examines the unique sensitivity shown by Pd/WO3 films that were fabricated via the use of the pulsed laser deposition technique on a substrate composed of porous silicon for the purpose of detecting hydrogen sulphide (H2S) and nitrogen dioxide (NO2) over a wide range of temperatures. Tungsten trioxide films doped with palladium (Pd/WO3) are fabricated using pulsed laser deposition at varying laser pulse energies (600, 800, and 1000 mJ/pulse). The ablation process involves the use of a Q-switched Nd/YAG laser operating at a wavelength of 532 nm. The laser system being examined demonstrates pulse duration of 10 ns and a frequency of 1 Hz when used on a porous silicon n-type Si (100) substrate. The study of Pd/WO3 nanoparticles involves the analysis of their crystal structure, optical properties, and morphology through various analytical methods such as X-ray diffraction, UV–Vis spectroscopy, Raman scattering, photoluminescence spectroscopy, and field-emission scanning electron microscopy. The increase in intensity of the pulse laser results in a heightened sharpness of the peaks detected in the Pd/WO3 thin film, indicating an enhancement in crystallinity. The dimensions of the surface particles have shown a rise, followed by a corresponding augmentation in the energy difference, resulting in a heightened degree of uniformity. The study aimed to examine the influence of Pd on the development kinetics of tungsten trioxide nanoparticles. The findings demonstrated that Pd had the capacity to augment sensitivity, reduce operational temperature, and maintain high sensitivity levels even at room temperature. The Pd/WO3 NPs/porous silicon device fabricated in this work, consisting of a Pd/WO3 nanostructure integrated with porous silicon, has remarkable potential as a high-efficiency gas sensor in several sensing technologies. [ABSTRACT FROM AUTHOR]

An extremely efficient green protocol for palladium acetate-catalysed ligand-free Suzuki–Miyaura cross-coupling reactions of aryl/heteroaryl bromides with aryl/substitute aryl boronic acids in neat 'Water Extract of Leaf Ash of Neem' (WELAN)' was developed. This method offers a simple, mild, efficient and highly cost-effective alternative to the existing protocols since the reaction proceeds in natural feedstock WELAN at room temperature in air at very short reaction times (5–60 min) under ligand/external base/promoter/organic medium free conditions. Here WELAN has been found to be the effective base and reaction medium for this cross-coupling reaction with high turnover number (TON). This manuscript also theoretically depicts the probable mechanism of WELAN catalysed cross-coupling reaction. [ABSTRACT FROM AUTHOR]

In this study, we investigate the electrochemical behavior of palladium nanoparticles (PdNP) deposition on glassy carbon electrode (GCE) in two deep eutectic solvents, namely, reline and ethaline, and its application in DNA sensors. The electrochemical behaviors of PdNP deposition are investigated by cyclic voltammetry and chronoamperometry. The obtained results indicate that the PdNP deposition on GCE in reline was dominated by the progressive 3D nucleation mechanism, while that in ethaline was dominated by the instantaneous nucleation mechanism. The structural, morphological, and compositional characteristics are also investigated through X-ray diffraction, field emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. A PdNP-based DNA sensor is constructed for Mycobacterium tuberculosis detection. Results indicate a significant difference between the DNA sensing responses based on the PdNPs synthesized in reline (PdNP-RE) and ethaline (PdNP-ET). The PdNP-ET–based DNA sensor has higher sensitivity than the PdNP-RE–based DNA sensor. This study serves as a reference for the development of improved nanomaterials for bioanalysis and the elaborate design of biosensors for practical applications. [ABSTRACT FROM AUTHOR]

In this research, a novel and efficient nanocatalyst, namely, palladium immobilized onto 1,4-bis(pyrid-4-yl)benzene grafted to n-propyl-functionalized Fe3O4@MCM-41 nanoparticles (PBPBPMF), was synthesized and introduced. Then, its catalytic activity was tested in the synthesis of bis(pyrazolyl)methane (14 examples, 90–97%, 9–25 min, solvent-free, 60 °C) and biphenyl (13 examples, 80–98%, 10–120 min, PEG-400, 70 °C) derivatives. Bis(pyrazolyl)methane derivatives were synthesized via a one-pot pseudo-five-component reaction of aldehydes, ethyl acetoacetate, and phenylhydrazine, and biphenyl derivatives were obtained by a Stille coupling reaction. Transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), N2 sorption isotherms, vibrating sample magnetometer (VSM), inductively coupled plasma atomic emission spectrometer (ICP-OES), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and elemental mapping analyses were used to identify the catalyst. The PBPBPMF is a heterogeneous catalyst with several advantages, including a large specific surface area, ease of purification, and separation from the reaction mixture; furthermore, the nanocatalyst was recycled six times without appreciably altering its catalytic properties. [ABSTRACT FROM AUTHOR]

Palladium nanoparticles (PdNPs) have emerged as promising metal nanoparticles in biomedical applications. In particular, green-synthesized PdNPs have gained significant attention due to their advantages of being simple, cost-effective, and low-toxic. This review summarizes the green synthesis of medicinal-oriented PdNPs using natural sources such as plants, mushrooms, algae, fungi, and biological molecules. Furthermore, this review discusses the potential biomedical applications of these green-synthesized PdNPs such as photothermal therapy, antibacterial/antitumor therapies, drug delivery, and imaging. It also identifies the current challenges and prospects for their use in these applications. Overall, this review demonstrates the promising potential of biogenic PdNPs for biomedical applications and provides valuable insights for future research in this field. [ABSTRACT FROM AUTHOR]

3-Methyl indanones are key synthetic building blocks for a variety of natural and useful synthetic compounds. Their synthesis is exceedingly difficult. Herein, we described a palladium (II) mediated intramolecular one-pot redox-relay cyclization of aromatic homoallylic alcohols to cyclic keto compounds. This catalytic system enabled direct conversion of homoallylic alcohols to corresponding indanones (3-methyl-1-indanones). Homoallylic alcohols were synthesized by reacting allyl magnesium bromide with corresponding aromatic aldehydes. The optimized reaction yielded up to 88% 3-methylindanones. Our findings enabled us to device a plausible mechanism for this one pot reaction. [ABSTRACT FROM AUTHOR]

To establish the dissolution mechanism of palladium (Pd) in the FetO–SiO2–CaO–Al2O3–MgOsat slag system, the Pd solubility was measured at 1873 K (1600 °C) and oxygen partial pressure ranging from p O 2 = 1.0 × 10 - 8 atm to p O 2 = 1.0 × 10 - 6 atm . In the current slag system, the Pd solubility increases with increasing content of CaO and FeO, and decreases with increasing content of SiO2 and Al2O3. This solubility behavior is quantified by employing the modified Vee ratio, defined as (CaO+FeO)/(SiO2+Al2O3), the theoretical optical basicity and the activity of CaO in the slag. Thermodynamic analysis reveals that Pd stabilizes in the form of the ( PdO 2 3 - ) palladate complex ion in the present aluminosilicate melts. Based on this, the Pd dissolution reaction in the current slag system is proposed as follows: Pd (l) + 1 4 O 2 (g) + 3 2 O 2 - = (PdO 2 3 -) Combining the results from the present experiment and previous findings suggests that a well-designed slag system can effectively minimize Pd loss during the pyrometallurgical processing of industrial wastes containing Pd. By adjusting the modified Vee ratio, in which CaO and FeO promote Pd solubility in the slag, whereas SiO2 increases slag viscosity, it is possible to achieve optimal conditions. Therefore, we recommend implementing such an optimized slag system for pyrometallurgical treatment of Pd-containing industrial wastes, ensuring minimal Pd loss and maximizing resource recovery. [ABSTRACT FROM AUTHOR]

The development of efficient Si–O bond formation reaction with 100% atom-economy, excellent functional group tolerance, and broad scope under mild conditions is highly desired due to the prevalence of silanol, silyl ether, and their derivatives in synthetic chemistry and materials science. Here, we have realized the Pd-catalyzed Si–O formation reaction via a Si–C activation approach with 100% atom-economy by employing silacyclobutanes (SCBs) and various hydroxy-containing substrates, including water, alcohols, phenols, and silanols. This protocol features a broad substrate scope, remarkable functional compatibility and mild conditions, providing a series of silanols, silyl ethers in high efficiency. Notably, this protocol could also be used for selective protection of hydroxy functionalities, and for the access of a class of novel polymers containing Si–O main chain. Preliminary mechanistic studies unveiled that this reaction underwent a Pd-catalyzed concerted ring-opening mechanism. [ABSTRACT FROM AUTHOR]

Designing reusable and stable catalysts with ease of synthesis is very important for chemical conversion reactions. Here, hierarchical Fe3O4 microspheres were prepared using facile surfactant free solvothermal method. Fe3O4 microspheres supported Chitosan/Pd nanocomposite was synthesized via cost-effective one-pot chemical reduction method. The nanocomposite was characterized using XRD, FTIR, SEM, EDX, FT-Raman and TGA analyses. XRD results confirm the presence of face-centered cubic-structured Fe3O4 and palladium in the nanocomposite. HRSEM images show monodispersed 3D hierarchical microspheres composed of nanospheres. The composite was found to have a superparamagnetic property due to the Fe3O4 microspheres and a combined magnetic saturation of 87.66 emu/g. The prepared material was tested for its catalytic performance toward reduction of 4-Nitrophenol(4-NP) to 4-Aminophenol(4-AP) and reaction followed the first-order kinetics with excellent catalytic performance. The incorporation of Fe3O4 microspheres in the composite significantly improved the stability and reusability. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) with a size range of 0.2 to 2 nm were prepared using a hydrothermal treatment of sucrose and oleic acid. The as-synthesized CDs were used to reduce H2PdCl4 to metallic Pd nanoparticles with dPd = 9.3 ± 3.7 nm, as confirmed by PXRD and HRTEM data. Pd particles were made to be larger than the CDs, to observe any inverse support effects, however, TEM data revealed that the CDs were transformed to carbon sheets in the reduction reaction at 100 °C. The synthesized Pd-CDs catalysts (0.81 wt. % loading) and CDs were both tested for the liquid phase hydrogenation of cinnamaldehyde. The influence of mass, temperature, and hydrogen flow rate on the activity and selectivity of the CDs and Pd-CDs catalyst on the hydrogenation of cinnamaldehyde was investigated. The CDs gave a cinnamaldehyde conversion (40%, 4 h) with selectivity towards the reduction of the C = O bond (cinnamyl alcohol) while the Pd-carbon catalyst was only selective to the reduction of the C = C bond (conversion 78%) indicating the dominance of Pd in the reaction. Post analysis of the deactivated catalysts indicated formation of carbon sheets and sintering of the Pd nanoparticles. It is thus shown that the presence of Pd induces the CDs to carbon sheet formation and thus indicates the limited use of CDs as a support for the olefin hydrogenation reaction with the CDs produced carbon support. This finding has implications for other studies using CDs as supports. [ABSTRACT FROM AUTHOR]

Using palladium-catalyzed arylation of (S)-2,2′-diamino-1,1′-binaphthalene (BINAM) with the halogen derivatives of naphthalene, anthracene, and anthraquinone, the corresponding N,N′-diaryl derivatives were synthesized. The dependence of the yields of the compounds on the structure of the initial halogen derivatives was shown. The synthesized compounds were studied in fluorescent enantioselective detection of amino alcohols. The synthesized derivatives demonstrate a response in the case of complex formation with some amino alcohols, but the response is most pronounced for the derivative with anthraquinone substituents. This detector can recognize enantiomers of leucinol, 2-phenylglycinol, and prolinol by different changes in the fluorescence enhancement in the presence of opposite optical isomers. In the case of 2-amino-1-propanol, fluorescence enhancement is observed only in the presence of the (S)-isomer. [ABSTRACT FROM AUTHOR]

We have achieved an efficient synthesis of C(3)-arylphthalides by coupling C(3)-bromophthalides and arylboronic acids under palladium catalysis. The C(sp3)-C(sp2) coupling worked well in the presence of water to provide products in a high yield. [ABSTRACT FROM AUTHOR]

Large surface area of electrocatalyst plays significant role in achieving high performance of water splitting. In this work, palladium–ruthenium (PdRu) binary alloys have been prepared via liquid phase deposition technique at low temperature. PdRu alloy with two dimensional nanosheets has been prepared at the growth temperature of 42 °C. The alloy is crystalline with the existence of minor phase of PdRu. The EDS mapping verifies the presence of Pd and Ru element in the alloy. The X-ray photoelectron spectroscopy (XPS) confirms the formation of PdRu. The sample tested in acidic solution yielded the highest current density and the lowest tafel slope value due to the lowest of charge transfer resistance with the value of 6 Ω. According to LSV measurement, the highest current density of 11.76 mA was yielded at the applied potential of 161 mV. The reduction current increases with the scanning rate with the highest reduction current of 1.8 mA cm−2 was obtained at the scanning rate of 10 mV/s. The electrocatalytic results of this work signify that PdRu nanosheets have potential to be utilized as efficient electrocatalyst for water splitting. [ABSTRACT FROM AUTHOR]

An experimental study of the normal spectral emissivity of technical nickel, palladium and platinum in the solid polished and liquid phases near the melting points was carried out by the radiation method. The emission measurement was recorded by the bandwidth of the applied narrowband filters. The dependence of metal emission on the wavelength in the range of the radiation spectrum 0.26–10.6 μm is obtained. A comparative analysis with the literature data of other authors is carried out. A theoretical calculation of the emission is given according to the classical electromagnetic theory Hagen's formula and Rubens. [ABSTRACT FROM AUTHOR]

A series of palladium (II) and platinum (II) selenolate complexes have been isolated depending upon the nature of the phosphine ligand. The substitution reaction of [PdCl2(PPh3)2] with two equivalents of NaSeC5H3(5-Me)N resulted in the hexanuclear complex [Pd6Br0.87Cl1.13{2-SeC5H3(5-Me)N2}2(PPh3)6] (1a) whereas a chelated compound [Pt{κ-Se, κ-N: SeC5H3(5-Me)N}{SeC5H3(5-Me)N}(PPh3)] (1b) has been obtained in the case of [PtCl2(PPh3)2]. However, chelated phosphine as an ancillary ligand with a similar reaction by using [PtCl2(P∩P)] (P∩P = dppm, dppe) yielded cis-configured monomer [Pt{2-SeC5H3(5-Me)N}2(P∩P)]. The trinuclear complexes [M3(µ-Se)3(dppp)3]2+ [M = Pd (2d), Pt (2e)] were isolated by reactions of [MCl2(dppp)] (M = Pd, Pt) with NaSeC5H3(5-Me)N via facile cleavage of Se-C bond in presence of chlorinated solvents. All the synthesized complexes have been characterized by elemental analyses, 1H, 31P{1H}, 77Se{1H} NMR spectroscopy. The molecular structure of complexes [Pd6Br0.87Cl1.13{2-SeC5H3(5-Me)}2(PPh3)6] (1a) and [Pt{2-SeC5H3(5-Me)N}2(dppm)].C6H5CH3 (2a) were determined by single crystal X-ray diffraction analyses. [ABSTRACT FROM AUTHOR]

Palladium (Pd)-based catalysts have received extensive attention for their outstanding performance in the complete oxidation of methane (CH4). A fundamental understanding of the reaction mechanism, particularly the most active phase, is essential for the development of efficient catalysts and the optimization of reaction conditions. By employing time-resolved ambient pressure X-ray photoelectron spectroscopy (tr-APXPS) and on-line mass spectrometer (MS), we investigated the complete oxidation of CH4 on the Pd(111) surface within a 1 mbar O2 + 0.25 mbar CH4 atmosphere, ranging from 600 to 900 K. Utilizing tr-APXPS enabled us to observe the phase transition of PdO → PdOx → O/Pd on the Pd(111) surface during the linear heating process. On-line MS data revealed that the formation of PdOx correlates with a significant increase in catalytic activity. By integrating the insights from APXPS and on-line MS, we propose that the catalytic activity for methane oxidation follows the order of PdOx > PdO > O/Pd. Furthermore, we suggest that the PdOx formed at the initial decomposition of bulk PdO is most active for dissociating methane. [ABSTRACT FROM AUTHOR]

In this study, the promoting effects of ruthenium, palladium, and copper on the performance of a 15%Co-1%K/SiO2 catalyst were evaluated during CO2 hydrogenation in a fixed-bed reactor. Reactions were carried out at atmospheric pressure and 270 °C with H2/CO2 ratio of 3. All catalysts were characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) and temperature-programmed reduction (TPR). Ruthenium, palladium and copper facilitated the reduction of cobalt oxides and increased cobalt dispersion. In terms of catalyst's performance, ruthenium addition led to increased CO2 conversion and methane selectivity with a detrimental effect on C5+ hydrocarbons. Palladium also presented a similar pattern at lower loading but a drop in CO2 conversion and increased reverse water–gas shift activity were observed at 3 wt % Pd loading. Promoting with copper resulted in decreased activity, methane selectivity and C5+ hydrocarbons productivity with a much higher CO selectivity. [ABSTRACT FROM AUTHOR]

Developing convenient and reliable methods for Hg2+ monitoring is highly important. Some precious metal nanomaterials with intriguing peroxidase-like activity have been used for highly sensitive Hg2+ detection. However, H2O2 must be added during these detections, which impedes practical applications of Hg2+ sensors due to its susceptible decomposition by environmental factors. Herein, we discovered that the combination of Hg2+ and palladium metal-organic framework@graphene (Pd-MOF@GNs) exhibits oxidase-like activity (OXD). In the absence of H2O2, this activity not only catalyzes the oxidation of chromogenic substrates such as 3,3',5,5'-tetramethylbenzidine (TMB) or o-phenylenediamine (OPD) to produce a color change but also enhances the electrical signals during OPD oxidation. Based on these properties, an effective and convenient dual-mode colorimetric and electrochemical sensor for Hg2+ has been developed. The colorimetric and amperometric linear relationships for Hg2+ were 0.045 μM—0.25 mM and 0.020 μM—2.0 mM, respectively. The proposed strategy shows good recovery in real sample tests, indicating promising prospects for multiple environmental sample detection of Hg2+ without relying on H2O2. The colorimetric and electrochemical dual-mode Hg2+ sensor is expected to hold great potentials in applications such as environmental monitoring, rapid field detection, and integration into smartphone detection of Hg2+. [ABSTRACT FROM AUTHOR]

Nanocomposite materials based on palladium, copper(I) oxide, and magnetite nanoparticles embedded in a nanocellulose matrix by precipitation and coprecipitation methods were obtained in situ and ex situ from solutions of the salts of the corresponding metals. Studies of the characteristics of the resulting composites using Fourier transform IR spectroscopy, X-ray diffraction, SEM, and TEM showed that the encapsulated nanoparticles have an insignificant effect on the morphology and structure of nanofibrillar cellulose. The catalytic properties of the nanocomposites were tested in the hydrogenation of nitrobenzene. [ABSTRACT FROM AUTHOR]

Platinum group metals (PGM) and cerium as one of the rare-earth elements are considered as critical raw materials, thus their recycling and re-use is of utmost importance. Among the PGMs, platinum (Pt), palladium (Pd), and rhodium (Rh) are the basic and most valuable metals used in catalytic converters. Due to the high price of PGMs, there are already recycling routes in Europe and especially in Germany. For PGM and rare-earth elements, research is focusing on greener, plain recovery techniques, which utilize milder reagents, offer better energy efficiency, and replace the existing recycling routes. In this work, a hydrometallurgical process is proposed to add a hydrometallurgy method to the mostly pyrometallurgical industrial recycling routes, resulting in recovery rates for cerium and PGMs of 63.21% and only 1.03% with sulfuric acid, respectively. With hydrochloric acid, the leaching efficiency for cerium is even lower, and for PGM it is comparable. In the method proposed in the present paper, the main PGMs remain in monoliths and can be recycled in existing recycling routes like pyrometallurgical recycling. [ABSTRACT FROM AUTHOR]

In the field of biomedical engineering, nanofiber scaffolds have excellent biomaterial properties, making them highly suitable for superior wound dressing applications. This work presents the fabrication of a novel bimetal blend comprising palladium and platinum nanoparticles integrated with silk fibroin and collagen composite nanofibers through the electrospinning method. The fabricated composite nanofibrous scaffolds were investigated to analyze their chemical composition, surface morphology, thermal stability, porosity, hemocompatibility, mechanical strength, swelling, and degradation properties. The average diameter length of the SF/CL/Pd–Pt composite nanofiber scaffolds is 141.62 ± 33.03 nm, with Pd and Pt nanoparticle diameters measured at 8.64 and 7.36 nm, respectively. In vitro assessments of SF/CL and SF/CL/Pd–Pt composite nanofiber scaffolds demonstrated outstanding antibacterial efficacy against both gram-positive (S. aureus) and gram-negative (E. coli) bacteria. The antioxidant activity of SF/CL/Pd–Pt composite nanofibers exhibited a free radical scavenging percentage of 94.34%. Additionally, cell proliferation studies conducted on the fibroblast (NIH3T3) cell line, along with in vivo investigations on male Sprague–Dawley rats, underscored the remarkable wound-healing ability of the SF/CL/Pd–Pt composite nanofiber scaffolds. Furthermore, histopathological examination of wounded tissue samples using H&E and Masson trichrome staining revealed faster reepithelialization, granulation, angiogenesis, and reduced inflammatory response. These findings demonstrate that SF/CL/Pd–Pt composite nanofibrous scaffolds are excellent wound dressing materials for all biomedical applications. [ABSTRACT FROM AUTHOR]

A comparative study of the magnetic properties of a palladium–cobalt alloy with an impurity content of up to 10 at % was made using calculations based on the density functional theory and experimental methods. It was found that the alloys had ferromagnetic ordering, which depended on the impurity concentration. At very low concentrations, less than 1 at %, the magnetic moment per impurity atom can reach 25µB. [ABSTRACT FROM AUTHOR]

Pd/ZrO2 and Pd/ZrO2SiO2 catalysts prepared by wet impregnation and reduced with H2 under mild (30°C, aqueous suspension) or harsh (320°C) conditions are compared in the hydrodechlorination of the microecotoxicant diclofenac (DCF) in an aqueous solution at 30°С. According to the TPR and XPS data, the addition of SiO2 to the support reduces the degree of metal-support interaction and facilitates the reduction of palladium. Despite the lower Pd0 fraction, the Pd/ZrO2 catalyst is more active in the batch reactor: after reduction at 320°С, it slightly, and after mild reduction, significantly (7 times), exceeds Pd/ZrO2SiO2 in catalytic activity. XRD and TEM show a wider size distribution of palladium nanoparticles in the Pd/ZrO2 sample, while low-temperature N2 adsorption, XPS, and TPR demonstrated better accessibility of palladium on the Pd/ZrO2 surface due to the reduced decoration by the support components and increased pore size. These features explain the increased activity of Pd/ZrO2. Testing in the flow system demonstrated higher DCF conversion in the presence of catalysts reduced at 320°C and higher stability of Pd/ZrO2SiO2 compared to Pd/ZrO2. The stability is ensured by the increased reducibility of Pd2+ with H2 and by the developed surface of Pd/ZrO2SiO2, which prevents deactivation under the action of HCl released in hydrodechlorination. [ABSTRACT FROM AUTHOR]

Hercynite magnetic nanoparticles were produced through the co-precipitation of ferrous and aluminum cations. The surface of hercynite was respectively coated with silica, 2,4,6-trichloro-1,3,5-triazine, and 1H-pyrazole-3,5-dicarboxylic acid to provide a suitable substrate for Pd(II) loading, furnishing Pd@Her-TCT-PDA. Subsequently, the introduced Pd(II) was reduced to Pd(0) using NaBH4. FT-IR, EDS, XRD, TGA, TEM and SEM images were the characteristic methods to prove the success of catalyst synthesis. The SEM image illustrated the particles with a nanosize of 25–50 nm and TEM image confirmed the presence of Pd nanoparticles with sizes lower than 2 nm. EDS elemental analysis of the catalyst proved the existence of Pd, Fe, and Al atoms along with the C, O, N, and Si atoms belong to the heterocyclic moieties. VSM analysis clarified a considerable drop in the magnetic properties of the hercynite core of the final catalyst due to its modified surface. TGA curve demonstrated that Pd@Her-TCT-PDA contains 20% organic content, attributed to the anchored heterocyclic ligands. Finally, Pd@Her-TCT-PDA was employed along with NaBH4 as a catalytic system to reduce completely the nitro group of aromatic compounds to their corresponding amines. The recyclability tests showed low drop in the catalytic activity of Pd@Her-TCT-PDA after third run with negligible leaching of Pd NPs. [ABSTRACT FROM AUTHOR]

Ag(Pd) bimetallic nanostructures (Ag(Pd)NPs) were synthesized using the galvanic replacement of palladium ions with silver nanoparticles. Based on a comparative analysis of the results of scanning electron microscopy, energy dispersive X-ray microanalysis, and X-ray powder diffraction, it was established that the obtained Ag(Pd)NPs can be considered as "core-shell" nanosystems, in which the core is silver, and the shells are palladium nanoparticles with a size of 5–15 nm. Ag(Pd)NPs were studied as catalysts for the aerobic liquid-phase oxidation of benzyl alcohol. The addition of Ag(Pd)NPs to the reaction system accelerates the reaction in 14 times. [ABSTRACT FROM AUTHOR]

Context: The combined use of transition metal-catalyzed C–H activation with aryne annulation reactions has emerged as an important strategy in organic synthesis. In this study, the mechanisms of the palladium(II)-catalyzed annulation reaction of N-methoxy amides and arynes were computationally investigated by density functional theory. The role of methoxy amide as a directing group was elucidated through the calculation of three different pathways for the C–H activation step, showing that the pathway where amide nitrogen acts as a directing group is preferable. At the reductive elimination transition state, an unstable seven-membered ring is formed preventing the lactam formation. A substituent effect study based on an NBO analysis, Hammet, and using a More O'Ferall-Jenks plot indicates that the C–H activation step proceeds via an electrophilic concerted metalation-deprotonation (eCMD) mechanism. The results show that electron-withdrawing groups increase the activation barrier and contribute to an early Pd–C bond formation and a late C–H bond breaking when compared with electron-donating substituents. Our computational results are in agreement with the experimental data provided in the literature. Methods: All calculations were performed using Gaussian 16 software. Geometry optimizations, frequency analyses at 393.15 K, and IRC calculations were conducted at the M06L/Def2-SVP level of theory. Corrected electronic energies, NBO charges, and Wiberg bond indexes were computed at the M06L/Def2-TZVP//M06L/Def2-SVP level of theory. Implicit solvent effects were considered in all calculations using the SMD model, with acetonitrile employed as the solvent. [ABSTRACT FROM AUTHOR]

The hydrocarboxylation of styrene in the presence of PdCl2(PPh3)2 was studied to investigate the influence of the nature of the solvent, promoters, and reaction conditions on the yield of the target 2-phenylpropionic acid. Cation exchange resins Amberlyst 15 and KU-2 were proposed as suitable alternatives to liquid acid promoters, making it possible to achieve a high catalytic activity with up to 99% regioselectivity. [ABSTRACT FROM AUTHOR]

Egg-shell catalysts PdAg/Al2O3 with a molar ratio of Ag: Pd ranging from 0.5 to 10 were synthesized in order to study the gas-phase hydrogenation of acetylene. The results obtained by IR spectroscopy of adsorbed CO and transmission electron microscopy confirm the assumption that a catalyst with an equimolar ratio Ag: Pd = 1 contains a substitutional solid solution, while at a ratio of Ag: Pd = 10 single-atom Pd1 sites, isolated from each other by silver atoms are formed. The results presented in this work demonstrate that the transformation of the active sites from the substitutional solid solution structure to the single-atom arrangement entails a considerable increase in selectivity toward the formation of ethylene. [ABSTRACT FROM AUTHOR]

Negishi cross-coupling reaction is a familiar reaction for the formation of carbon–carbon bonds that couples organic halides or triflates with organozinc compounds. Palladium is used as a metal catalyst, sometimes nickel can also be used, e.g. Pd2(dba)3, PdCl2(P(otol)3)2, Pd(DPEPhos)Cl2, Ni(PPh3)2Cl2, etc. This reaction has vast applications in organic synthesis as many natural products and biologically active compounds can be obtained through this reaction. The main aim of this review is to summarize the recent synthetic applications of the Negishi reaction reported since 2011 which may be helpful to the researchers working on the development of mild and sustainable strategies regarding the synthesis of pharmaceutically important scaffolds. [ABSTRACT FROM AUTHOR]

The palladium anchored to BisPyP@bilayer-SiO2@NMP organic–inorganic hybrid was employed as an effective and recyclable organometallic catalyst in Suzuki and Stille C–C coupling reactions. The structure of this magnetic nanocatalyst was determined using various techniques such as SEM, TEM, FT-IR, EDS, ICP-OES, VSM, N2 adsorption–desorption isotherms, XRD, and TGA. In both of the mentioned coupling paths, the yields of the products were very favorable and ranged from 90 to 98%. Also, they had significant features compared to previous reports, such as very short reaction time (5–15 and 7–20 min respectively in the Suzuki and Stille reactions), easy work-up, broad substrate scope, ease of separation of the catalyst using a magnet, suitable reproducibility of the catalyst in 6 runs, heterogeneous nature of the catalyst and not washing it during consecutive runs with confirmation of hot filtration and ICP-OES methods. [ABSTRACT FROM AUTHOR]

The electrical properties of Pd/InP Schottky diodes and Pd-layers deposited on glass substrate by thermal evaporation in vacuum, and placed in hydrogen medium containing 10–100 vol % of hydrogen, were studied. The current generation in Pd/InP Schottky diodes, as well as the decrease in resistance of Pd layers were observed in hydrogen medium. It is proposed that the current generation in the structures under study is due to free electrons as result of hydrogen atoms ionization. The current induced by these electrons exists in electric circuit until hydrogen is present in the environment. It is shown that the hydrogen current generators can be created based on the Pd/InP diode structure. [ABSTRACT FROM AUTHOR]

The properties of Pd/HZSM-5 and Pd–nP/HZSM-5 catalysts were studied in direct synthesis and side processes of decomposition and hydrogenation of H2O2 under mild conditions in ethanol and aqueous ethanol in the presence of an acid inhibitor. It was shown, using HRTEM, XRD, and ICP MS methods, that modification with phosphorus led to the formation of highly dispersed X-ray amorphous systems, which are structurally disordered solid solutions of phosphorus in palladium. The main factors governing the promoting effect of phosphorus on the yield of H2O2 are considered. It was established that the use of a zeolite support in the H form, along with the phosphorus and acid modifiers, inhibits the side process of H2O2 decomposition. [ABSTRACT FROM AUTHOR]

Iron oxide-modified 1Pd0.5Fe and 1Pd10Fe catalysts with a target content of 1 wt % Pd and 0.5 or 10 wt % Fe have been synthesized by the wet impregnation of Al2O3 with iron and palladium nitrates. The catalysts have been compared with each other and with a monometallic 1Pd catalyst in diclofenac (DCF) hydrodechlorination (HDC) in dilute aqueous solutions at 30°C in batch and flow reactors after high-temperature (320°C) and mild reduction (30°C), the latter being run in a batch or flow reactor. X-ray photoelectron spectroscopy (XPS) has revealed that, after reduction at 320°C, the catalysts contain mostly Pd0, Fe2+, and Fe3+. The Fe2+/Fe3+ ratio on the surface increases with a decrease in the iron content. The reduction of Pd2+ to Pd0 can occur even at 30°C; however, on the 1Pd0.5Fe surface, it is significantly less effective than that on 1Pd10Fe. According to XPS, temperature-programmed reduction, and diffuse reflectance infrared Fourier transform spectroscopy of adsorbed CO, modification with iron oxides leads to an increase in the palladium content on the surface compared with that on 1Pd, contributes to the formation of new Pd–O–Fe sites, and affects the reducibility of palladium. These effects enhance with an increase in the iron content. The iron-modified catalysts reduced at 320°C exhibit similar activity and stability in DCF conversion in flow and batch systems. The 1Pd10Fe catalyst, unlike 1Pd0.5Fe, is highly efficient and stable even after mild reduction at 30°C. Under flow conditions, it provides a DCF conversion comparable to that provided by 1Pd and a selectivity in the DCF HDC reaction that is higher than that provided by 1Pd, which is also active in hydrogenation. [ABSTRACT FROM AUTHOR]

This paper demonstrates that relative reactivity estimated under competition of several similar substrates can be applied to visualize the dynamics of changes in a catalyst under the conditions of a complex catalytic process. The fundamental advantage of the proposed approach is that the state of an active catalyst can be monitored throughout the catalytic reaction without differentiation of the kinetic data on the concentrations of reacted substances. [ABSTRACT FROM AUTHOR]