scholarly journals Hydrogen Production from Formic Acid Attained by Bimetallic Heterogeneous PdAg Catalytic Systems

Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4027 ◽  
Author(s):  
Miriam Navlani-García ◽  
David Salinas-Torres ◽  
Diego Cazorla-Amorós
Keyword(s):  
Formic Acid ◽  
High Performance ◽  
Heterogeneous Catalysts ◽  
Carbon Materials ◽  
Pd Nanoparticles ◽  
Catalytic Performance ◽  
Catalytic Systems ◽  
Storage Technologies ◽  
The Impact ◽  
Great Focus

The production of H2 from the so-called Liquid Organic Hydrogen Carriers (LOHC) has recently received great focus as an auspicious option to conventional hydrogen storage technologies. Among them, formic acid, the simplest carboxylic acid, has recently emerged as one of the most promising candidates. Catalysts based on Pd nanoparticles are the most fruitfully investigated, and, more specifically, excellent results have been achieved with bimetallic PdAg-based catalytic systems. The enhancement displayed by PdAg catalysts as compared to the monometallic counterpart is ascribed to several effects, such as the formation of electron-rich Pd species or the increased resistance against CO-poisoning. Aside from the features of the metal active phases, the properties of the selected support also play an important role in determining the final catalytic performance. Among them, the use of carbon materials has resulted in great interest by virtue of their outstanding properties and versatility. In the present review, some of the most representative investigations dealing with the design of high-performance PdAg bimetallic heterogeneous catalysts are summarised, paying attention to the impact of the features of the support in the final ability of the catalysts towards the production of H2 from formic acid.

scholarly journals Selective Styrene Oxidation to Benzaldehyde over Recently Developed Heterogeneous Catalysts

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1680
Author(s):  
Marta A. Andrade ◽  
Luísa M. D. R. S. Martins
Keyword(s):  
Heterogeneous Catalysts ◽  
Carbon Materials ◽  
Oxygen Species ◽  
Styrene Oxidation ◽  
Reaction Conditions ◽  
Reactive Metal ◽  
Catalytic Systems ◽  
Tert Butyl Hydroperoxide ◽  
Metal Organic ◽  
Important Intermediate

The selective oxidation of styrene under heterogeneous catalyzed conditions delivers environmentally friendly paths for the production of benzaldehyde, an important intermediate for the synthesis of several products. The present review explores heterogeneous catalysts for styrene oxidation using a variety of metal catalysts over the last decade. The use of several classes of supports is discussed, including metal–organic frameworks, zeolites, carbon materials and silicas, among others. The studied catalytic systems propose as most used oxidants tert-butyl hydroperoxide, and hydrogen peroxide and mild reaction conditions. The reaction mechanism proceeds through the generation of an intermediate reactive metal–oxygen species by catalyst-oxidant interactions. Overall, most of the studies highlight the synergetic effects among the metal and support for the activity and selectivity enhancement.

scholarly journals Preformed Pd-Based Nanoparticles for the Liquid Phase Decomposition of Formic Acid: Effect of Stabiliser, Support and Au–Pd Ratio

2020 ◽  
Vol 10 (5) ◽  
pp. 1752 ◽  
Author(s):  
Felipe Sanchez ◽  
Ludovica Bocelli ◽  
Davide Motta ◽  
Alberto Villa ◽  
Stefania Albonetti ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Formic Acid ◽  
Pd Nanoparticles ◽  
Catalytic Performance ◽  
Atomic Ratio ◽  
Phase Decomposition ◽  
Acid Effect ◽  
Formic Acid Decomposition ◽  
Structure Morphology

Hydrogen is one of the most promising energy carriers for the production of electricity based on fuel cell hydrogen technology. Recently, hydrogen storage chemicals, such as formic acid, have been proposed to be part of the long-term solution towards hydrogen economy for the future of our planet. Herein we report the synthesis of preformed Pd nanoparticles using colloidal methodology varying a range of specific experimental parameters, such as the amount of the stabiliser and reducing agent, nature of support and Pd loading of the support. The aforementioned parameters have shown to affect mean Pd particle size, Pd oxidation, atomic content of Pd on the surface as well as on the catalytic performance towards formic acid decomposition. Reusability studies were carried out using the most active monometallic Pd material with a small loss of activity after five uses. The catalytic performance based on the Au–Pd atomic ratio was evaluated and the optimum catalytic performance was found to be with the Au/Pd atomic ratio of 1/3, indicating that the presence of a small amount of Pd is essential to promote significantly Au activity for the liquid phase decomposition of formic acid. Thorough characterisation has been carried out by means of XPS, SEM-EDX, TEM and BET. The observed catalytic performance is discussed in terms of the structure/morphology and composition of the supported Pd and Au–Pd nanoparticles.

scholarly journals Ultrafine Pd Nanoparticles Supported on Soft Nitriding Porous Carbon for Hydrogen Production from Hydrolytic Dehydrogenation of Dimethyl Amine-Borane

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1612
Author(s):  
Zhaoyu Wen ◽  
Qiong Fu ◽  
Jie Wu ◽  
Guangyin Fan
Keyword(s):  
Porous Carbon ◽  
High Performance ◽  
Hydrogen Generation ◽  
Pd Nanoparticles ◽  
Catalytic Performance ◽  
Pd Catalysts ◽  
Nano Catalyst ◽  
Dimethyl Amine ◽  
Catalytic Hydrogen ◽  
Hydrolysis Of

Simple and efficient synthesis of a nano-catalyst with an excellent catalytic property for hydrogen generation from hydrolysis of dimethyl amine-borane (DMAB) is a missing piece. Herein, effective and recycled palladium (Pd) nanoparticles (NPs) supported on soft nitriding porous carbon (NPC) are fabricated and applied for DMAB hydrolysis. It is discovered that the soft nitriding via a low-temperature urea-pretreatment induces abundant nitrogen-containing species on the NPC support, thus promoting the affinity of the Pd precursor and hindering the agglomeration of formed Pd NPs onto the NPC surface during the preparation process. Surface-clean Pd NPs with a diameter of sub-2.0 nm deposited on the NPC support (Pd/NPC) exhibit an outstanding catalytic performance with a turnover frequency (TOF) of 2758 h−1 toward DMAB hydrolysis, better than many previous reported Pd-based catalysts. It should be emphasized that the Pd/NPC also possesses a good stability without an obvious decrease in catalytic activity for DMAB hydrolysis in five successive recycling runs. This study provides a facile but efficient way for preparing high-performance Pd catalysts for catalytic hydrogen productions.

scholarly journals Anchoring Pd-nanoparticles on dithiocarbamate- functionalized SBA-15 for hydrogen generation from formic acid

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mustafa Farajzadeh ◽  
Hassan Alamgholiloo ◽  
Fariba Nasibipour ◽  
Reza Banaei ◽  
Sadegh Rostamnia
Keyword(s):  
Formic Acid ◽  
Ultrasonic Irradiation ◽  
Large Scale ◽  
Hydrogen Generation ◽  
High Surface ◽  
High Surface Area ◽  
Pd Nanoparticles ◽  
Metal Nanoparticle ◽  
Catalytic Systems ◽  
Metabolic Products

Abstract Hydrogen (H2) generation from natural biological metabolic products has remained a huge challenge for the energy arena. However, designing a catalytic system with complementary properties including high surface area, high loading, and easy separation offers a promising route for efficient utilization of nanoreactors for prospective H2 suppliers to a fuel cell. Herein, selective dehydrogenation of formic acid (FA) as a natural biological metabolic product to H2 and CO2 gas mixtures has been studied by supporting ultrafine palladium nanoparticles on organosulfur-functionalized SBA-15 nanoreactor under ultrasonic irradiation. The effects of the porous structure as a nanoreactor, and organosulfur groups, which presented around the Pd due to their prominent roles in anchoring and stabilizing of Pd NPs, studied as a superior catalyst for selective dehydrogenation of FA. Whole catalytic systems were utilized in ultrasonic irradiation in the absence of additives to provide excellent TOF/TON values. It was found that propose catalyst is a greener, recyclable, and more suitable option for the large-scale application and provide some new insights into stabilization of ultra-fine metal nanoparticle for a variety of applications.

scholarly journals Bimetallic Zr,Zr-Hydride Complexes in Zirconocene Catalyzed Alkene Dimerization

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2216
Author(s):  
Lyudmila V. Parfenova ◽  
Pavel V. Kovyazin ◽  
Almira Kh. Bikmeeva
Keyword(s):  
High Performance ◽  
Direct Evidence ◽  
Catalytic Performance ◽  
High Yield ◽  
Nmr Studies ◽  
Catalytic Systems ◽  
Synthetic Compounds ◽  
Precise Control ◽  
Hydride Complexes ◽  
Active Intermediates

Being valuable precursors in the production of adhesives, lubricants, and other high-performance synthetic compounds, alkene dimers and oligomers can be obtained using homogeneous zirconocene catalytic systems. Further advances in such systems require precise control of their activity and chemoselectivity, increasing both the purity and yield of the products. This relies on the process mechanism usually built around the consideration of the hydride complexes as active intermediates in the alkene di- and oligomerization; however, the majority of studies lack the direct evidence of their involvement. Parallel studies on a well-known Cp2ZrCl2-AlR3 or HAlBui2 and a novel [Cp2ZrH2]2-ClAlR2 (R = Me, Et, Bui) systems activated by methylaluminoxane (MMAO-12) have shown a deep similarity both in the catalytic performance and intermediate composition. As a result of the NMR studies, among all the intermediates considered, we proved that new Zr,Zr- hydride complexes having the type x[Cp2ZrH2∙Cp2ZrHCl∙ClAlR2]∙yMAO appear to be specifically responsible for the alkene dimerization with high yield.

Salen–porphyrin-based conjugated microporous polymer supported Pd nanoparticles: highly efficient heterogeneous catalysts for aqueous C–C coupling reactions

2019 ◽  
Vol 7 (6) ◽  
pp. 2660-2666 ◽  
Author(s):  
Pengyao Ju ◽  
Shujie Wu ◽  
Qing Su ◽  
Xiaodong Li ◽  
Ziqian Liu ◽  
...  
Keyword(s):  
High Performance ◽  
Heterogeneous Catalysts ◽  
Pd Nanoparticles ◽  
Coupling Reactions ◽  
Highly Efficient ◽  
Conjugated Microporous Polymer ◽  
Microporous Polymer ◽  
Polymer Supported ◽  
Supported Pd

Salen–porphyrin-based CMP supported Pd nanoparticles were employed as high-performance heterogeneous catalysts for aqueous Suzuki–Miyaura and Heck–Mizoroki coupling reactions.

scholarly journals Learning design rules for selective oxidation catalysts from high-throughput experimentation and artificial intelligence

2021 ◽  
Author(s):  
Lucas Foppa ◽  
Christopher Sutton ◽  
Luca M. Ghiringhelli ◽  
Sandip De ◽  
Patricia Löser ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
High Performance ◽  
Heterogeneous Catalysts ◽  
Supported Catalysts ◽  
Value Added ◽  
Theoretical Data ◽  
Catalytic Performance ◽  
Subgroup Discovery ◽  
Data Set ◽  
High Yields

The design of heterogeneous catalysts is challenged by the complexity of materials and processes that govern reactivity and by the fact that the number of good catalysts is very small compared to the number of possible materials. Here, we show how the subgroup-discovery (SGD) artificial-intelligence approach can be applied to an experimental plus theoretical data set to identify constraints on key physicochemical parameters, the so-called SG rules, which exclusively describe materials and reaction conditions with outstanding catalytic performance. By using high-hroughput experimentation, 120 SiO 2 -supported catalysts containing ruthenium, tungsten and phosphorus were synthesized and tested in the catalytic oxidation of propylene. As candidate descriptive parameters, the temperature and ten parameters related to the composition and chemical nature of the catalyst materials, derived from calculated free-atom properties, were offered. The temperature, the phosphorus content, and the composition-weighted electronegativity are identified as key parameters describing high yields towards the value-added oxygenate products acrolein and acrylic acid. The SG rules not only reflect the underlying processes particularly associated to high performance but also guide the design of more complex catalysts containing up to five elements in their composition.

In situ synthesis and encapsulation of copper phthalocyanine into MIL-101(Cr) and MIL-100(Fe) pores and investigation of their catalytic performance in the epoxidation of styrene

2019 ◽  
Vol 23 (10) ◽  
pp. 1118-1131 ◽  
Author(s):  
Ardeshir Dadgar Yeganeh ◽  
Mostafa M. Amini ◽  
Nasser Safari
Keyword(s):  
Electron Microscopy ◽  
Heterogeneous Catalysts ◽  
Copper Phthalocyanine ◽  
Deep Eutectic Solvent ◽  
Catalytic Performance ◽  
Active Species ◽  
Icp Oes ◽  
Tert Butyl Hydroperoxide ◽  
Ft Ir ◽  
The Impact

In this work, copper phthalocyanine (CuPc) was encapsulated into mesocages of MIL-101(Cr) and MIL-100(Fe) by assembling CuPc’s constitutional fractions using a deep eutectic solvent. The prepared materials, CuPc@MIL-101(Cr) and CuPc@MIL-100(Fe), were characterized by powder X-ray diffraction (PXRD), FT-IR, UV-vis and diffuse reflectance UV (DR-UV) spectroscopies, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and ICP-OES spectrometry. The prepared materials were used as heterogeneous catalysts for catalytic epoxidation of styrene with molecular oxygen and also tert-butyl hydroperoxide (TBHP) as oxidants in acetonitrile as a solvent. The impact of MOFs and the role of the CuPc complex as the active species in the MOFs’ cages in the epoxidation of styrene were investigated. Among the prepared catalysts, CuPc@MIL-101(Cr) showed the best performance. The heterogeneity of the catalysts was examined by a hot filtration test and ICP-OES of the filtrates after the reaction. Spent catalysts were analyzed by PXRD, FT-IR, UV-DRS, and TEM for reusability investigation and also to further explore the heterogeneous nature of the hybrid materials. Results showed that the prepared catalysts could be recycled and used for several concoctive times without a considerable drop in activity.

Graphene hydrogel supported palladium nanoparticles as an efficient and reusable heterogeneous catalysts in the transfer hydrogenation of nitroarenes using ammonia borane as a hydrogen source

2018 ◽  
Vol 90 (2) ◽  
pp. 327-335 ◽  
Author(s):  
Paria Eghbali ◽  
Bilal Nişancı ◽  
Önder Metin
Keyword(s):  
Heterogeneous Catalysts ◽  
Pd Nanoparticles ◽  
Ammonia Borane ◽  
Catalytic Performance ◽  
Transfer Hydrogenation ◽  
Bet Surface Area ◽  
Tandem Reactions ◽  
One Pot ◽  
Hydrogenation Reactions ◽  
Catalytic Cycles

Abstract Addressed herein is a facile one-pot synthesis of graphene hydrogel (GHJ) supported Pd nanoparticles (NPs), namely Pd-GHJ nanocomposites, via a novel method that comprises the combination of hydrothermal treatment and polyol reduction protocols in water. The structure Pd-GHJ nanocomposites were characterized by TEM, HR-TEM, XRD, XPS, Raman spectroscopy and BET surface area analysis. Then, Pd-GHJ nanocomposites were used as a heterogeneous catalysts in the tandem dehydrogenation of ammonia borane and hydrogenation of nitroarenes (Ar–NO2) to anilines (Ar–NH2) in the water/methanol mixture at room temperature. A variety of Ar–NO2 derivatives (total 9 examples) were successfully converted to the corresponding Ar–NH2 by the help of Pd-GHJ nanocomposites catalyzed tandem reactions with the conversion yields reaching up to 99% in only 20 min reaction time. Moreover, Pd-GHJ nanocomposites were demonstrated to be the reusable catalysts in the tandem reactions by preserving their initial catalytic performance after five consecutive catalytic cycles. It is believed that the presented synthesis protocol for the Pd-GHJ nanocomposites and the catalytic tandem hydrogenation reactions will make a significant contribution to the catalysis and synthetic organic chemistry fields.

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