Ni-based bimetallic heterogeneous catalysts for energy and environmental applications

The depolymerization of lignin to bioaromatics usually requires a hydrodeoxygenation (HDO) step to lower the oxygen content. A mixed Cu–Mg–Al oxide (CuMgAlOx) is an effective catalyst for the depolymerization of lignin in supercritical ethanol. We explored the use of Ni-based cocatalysts, i.e. Ni/SiO2, Ni2P/SiO2, and Ni/ASA (ASA = amorphous silica alumina), with the aim of combining lignin depolymerization and HDO in a single reaction step. While the silica-supported catalysts were themselves hardly active in lignin upgrading, Ni/ASA displayed comparable lignin monomer yield as CuMgAlOx. A drawback of using an acidic support is extensive dehydration of the ethanol solvent. Instead, combining CuMgAlOx with Ni/SiO2 and especially Ni2P/SiO2 proved to be effective in increasing the lignin monomer yield, while at the same time reducing the oxygen content of the products. With Ni2P/SiO2, the lignin monomer yield was 53 wt %, leading to nearly complete deoxygenation of the aromatic products.

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“…34 Ni-based heterogeneous catalysts for energy and environmental applications have been recently reviewed. 35 …”

Section: Introductionmentioning

confidence: 99%

Synergy in Lignin Upgrading by a Combination of Cu-Based Mixed Oxide and Ni-Phosphide Catalysts in Supercritical Ethanol

Korányi

Huang

Coumans

et al. 2017

ACS Sustainable Chem. Eng.

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“…26 Unlike catalysis-based water treatment methods, ETAS does not decompose organics chemically, and in fact can achieve nearly 100% recovery for many species tested here, which is often a key achievement goal for separation technologies. More importantly, ETAS possesses a number of advantageous characteristics not shared by electrocatalysis.…”

Section: Introductionmentioning

confidence: 99%

Energetically efficient electrochemically tunable affinity separation using multicomponent polymeric nanostructures for water treatment

Mao

Tian

Ren

et al. 2018

Energy Environ. Sci.

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We describe a water treatment strategy, electrochemically tunable affinity separation (ETAS), which, unlike other previously developed electrochemical processes, targets uncharged organic pollutants in water. Key to achieving ETAS resides in the development of multicomponent polymeric nanostructures that simultaneously exhibit the following characteristics: an oxidation-state dependent affinity towards neutral organics, high porosity for sufficient adsorption capacity, and high conductivity to permit electrical manipulation. A prototype ETAS adsorbent composed of nanostructured binary polymeric surfaces that can undergo an electrically-induced hydrophilic-hydrophobic transition can provide programmable control of capture and release of neutral organics in a cyclic fashion. A quantitative energetic analysis of ETAS offers insights into the tradeoff between energy cost and separation extent through manipulation of electrical swing conditions. We also introduce a generalizable materials design approach to improve the separation degree and energetic efficiency simultaneously, and identify the critical factors responsible for such enhancement via redox electrode simulations and theoretical calculations of electron transfer kinetics. The effect of operation mode and multistage configuration on ETAS performance is examined, highlighting the practicality of ETAS and providing useful guidelines for its operation at large scale. The ETAS approach is energetically efficient, environmentally friendly, broadly applicable to a wide range of organic contaminants of various molecular structures, hydrophobicity and functionality, and opens up new avenues for addressing the urgent, global challenge of water purification and wastewater management. Broader contextSeparation processes are of paramount importance in the chemical and environmental industries, accounting for 10-25% of the world's energy consumption, and about a third of total capital and operation costs in industrial plants. The development of separation technologies for water treatment with high energy efficiency and low environmental impact has become a primary engineering challenge for the 21st century due to the worldwide occurrence of water contamination and its associated negative impacts on the environment and human health. Electrochemically controlled processes, such as capacitive deionization, have emerged as promising candidates for wastewater management and water desalination. However, since these previously developed electrochemical methods rely primarily on the electrostatic interaction between the electrode and the target pollutant, they only work for charged species (e.g., anions, cations), and are not applicable to uncharged organic pollutants, which constitute the majority of industrial and municipal water contaminants, including many dyes, pesticides, pharmaceuticals and carcinogenic aromatics. This study investigates a conceptually novel separation strategy that enables sensitive, programmable electrochemical control over the release and capture of u...

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“…With respect to other PGM elements, palladium is characterized by a fundamental electronic configuration unique among transition metals (4d 10 , 5s 0 ) [107] that can be strongly influenced by the coordination environment [108]. The modification of catalytic properties of palladium by adding a second metal can be related, from a general point of view, in terms of (i) "ligand" effects (related to shifting of the d-band density); (ii) "ensemble" effect (a dilution of palladium surface by a relatively unreactive second co-metal); (iii) "stabilizing" effect (improving the active sites stability) [109][110][111][112][113][114]. Hence, heterogeneous catalysts based on palladium bimetallic systems have gained increasing attention for their enhanced activity and durability in different reactions .…”

Section: Introductionmentioning

confidence: 99%

Upgrading Lignocellulosic Biomasses: Hydrogenolysis of Platform Derived Molecules Promoted by Heterogeneous Pd-Fe Catalysts

et al. 2017

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Abstract:This review provides an overview of heterogeneous bimetallic Pd-Fe catalysts in the C-C and C-O cleavage of platform molecules such as C2-C6 polyols, furfural, phenol derivatives and aromatic ethers that are all easily obtainable from renewable cellulose, hemicellulose and lignin (the major components of lignocellulosic biomasses). The interaction between palladium and iron affords bimetallic Pd-Fe sites (ensemble or alloy) that were found to be very active in several sustainable reactions including hydrogenolysis, catalytic transfer hydrogenolysis (CTH) and aqueous phase reforming (APR) that will be highlighted. This contribution concentrates also on the different synthetic strategies (incipient wetness impregnation, deposition-precipitaion, co-precipitaion) adopted for the preparation of heterogeneous Pd-Fe systems as well as on the main characterization techniques used (XRD, TEM, H 2 -TPR, XPS and EXAFS) in order to elucidate the key factors that influence the unique catalytic performances observed.

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Ni-based bimetallic heterogeneous catalysts for energy and environmental applications

Abstract: This review provides a comprehensive overview of nickel based bimetallic catalysts for energy and environmental applications.

Cited by 586 publications

References 357 publications

Synergy in Lignin Upgrading by a Combination of Cu-Based Mixed Oxide and Ni-Phosphide Catalysts in Supercritical Ethanol

Synergy in Lignin Upgrading by a Combination of Cu-Based Mixed Oxide and Ni-Phosphide Catalysts in Supercritical Ethanol

Energetically efficient electrochemically tunable affinity separation using multicomponent polymeric nanostructures for water treatment

Upgrading Lignocellulosic Biomasses: Hydrogenolysis of Platform Derived Molecules Promoted by Heterogeneous Pd-Fe Catalysts

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