498-00-0Relevant articles and documents
Hydrodeoxygenation of vanillin over carbon nanotube-supported Ru catalysts assembled at the interfaces of emulsion droplets
Yang, Xiaomin,Liang, Yu,Cheng, Yanyan,Song, Wei,Wang, Xiaofeng,Wang, Zichen,Qiu, Jieshan
, p. 28 - 31 (2014)
Carbon nanotube supported ruthenium catalysts, assembled at the water/oil interfaces, show excellent activity and selectivity for the hydrodeoxygenation of the bio-oil model compound of vanillin under mild conditions (1 MPa, 150 C). Based on a direct fluorescence image, the Ru/CNT catalysts are mainly distributed on the surface of the emulsion droplets, forming a Pickering emulsion. Simultaneous reaction and separation of the products are achieved in the constructed emulsions, which have great potential in the simplifications of the isolation and purification stages for bio-oil refining.
Highly dispersed nickel anchored on a N-doped carbon molecular sieve derived from metal-organic frameworks for efficient hydrodeoxygenation in the aqueous phase
Fan, Ruoyu,Fan, Ruoyu,Hu, Zhi,Hu, Zhi,Chen, Chun,Zhu, Xiaoguang,Zhang, Haimin,Zhang, Yunxia,Zhao, Huijun,Zhao, Huijun,Wang, Guozhong
, p. 6696 - 6699 (2020)
ZIF-8 was employed as a template to synthesize HD-Ni/N-CMS containing highly dispersed Ni at the atomic level anchored on a N-doped carbon molecular sieve for vanillin hydrodeoxygenation. The ZIF-8 structure was inherited and Ni-N bonds were formed by the coordination of Ni with N-rich defects, therefore it exhibited a high turnover frequency (1047.1 h-1) and good stability.
Au/CNTs catalyst for highly selective hydrodeoxygenation of vanillin at the water/oil interface
Yang, Xiaomin,Liang, Yu,Zhao, Xu,Song, Yifan,Hu, Lianghai,Wang, Xiaofeng,Wang, Zichen,Qiu, Jieshan
, p. 31932 - 31936 (2014)
Au/CNTs assembled at the interfaces of a Pickering emulsion are reported, for the first time, exhibiting good catalytic activity and 100% selectivity for the hydrodeoxygenation of vanillin to p-creosol under mild reaction conditions. Simultaneous reaction and separation of the target products are achieved, which leads to substantial simplification of the separation and purification process for bio-oil upgrading.
Cobalt Nanoparticles Supported on Nitrogen-Doped Carbon: An Effective Non-Noble Metal Catalyst for the Upgrade of Biofuels
Jiang, Liang,Zhou, Peng,Liao, Chanjuan,Zhang, Zehui,Jin, Shiwei
, p. 959 - 964 (2018)
A new method has been developed for the deoxygenation of vanillin to produce 2-methoxy-4-methylphenol (MMP) as a promising liquid fuel over a heterogeneous non-noble metal catalyst. Cobalt nanoparticles supported on nitrogen-doped carbon (Co/N-C-600) exhibit high activity and stability for the deoxygenation of vanillin into MMP under mild conditions (150 °C, 10 bar H2). Nearly quantitative MMP yield is obtained in isopropanol after 8 h at 150 °C and 10 bar H2 pressure. According to the distribution of products with time, the deoxygenation of vanillin into MMP mainly proceeds through the hydrogenation of vanillin into vanillyl alcohol and the subsequent hydrogenolysis of vanillyl alcohol into MMP, of which the latter is the rate-determining step, owing to a much higher activation energy. Moreover, after being recycled several times, the loss of catalytic activity is negligible, which demonstrates that the Co/N-C-600 catalyst shows good resistance to deactivation.
Surfactant-free Pd nanoparticles immobilized to a metal-organic framework with size- and location-dependent catalytic selectivity
Aijaz, Arshad,Zhu, Qi-Long,Tsumori, Nobuko,Akita, Tomoki,Xu, Qiang
, p. 2577 - 2580 (2015)
Surfactant-free Pd nanoparticles, immobilized to a metal-organic framework (MIL-101), have been used for the first time as highly active and durable catalysts in water for biomass refining (hydrodeoxygenation of vanillin, a typical compound of lignin) with metal nanoparticle size- and location-dependent catalytic activity and selectivity. This journal is
A general approach towards efficient catalysis in Pickering emulsions stabilized by amphiphilic RGO-Silica hybrid materials
Wei, Xu-Rui,Liu, Jun,Yang, Yong,Deng, Li
, p. 35744 - 35749 (2014)
A general approach towards efficient emulsion catalysis has been achieved using amphiphilic RGO-silica hybrid materials with suitable surface wettability and mesoporous structures. On the basis of the promising hybrids, a Pickering emulsion with droplets from 20-100 μm was formed and a broad range of reactions was facilitated.
Synergetic catalysis of palladium nanoparticles encaged within amine-functionalized UiO-66 in the hydrodeoxygenation of vanillin in water
Zhang, Fumin,Zheng, Shuang,Xiao, Qiang,Zhong, Yijun,Zhu, Weidong,Lin, Andrew,Samy El-Shall
, p. 2900 - 2908 (2016)
Ultrasmall palladium nanoparticles (1.5-2.5 nm) encapsulated in metal-organic frameworks (MOFs) have been prepared by introducing a palladium precursor into a highly porous and hydrothermally stable amine-functionalized UiO-66 (NH2-UiO-66) via a direct anionic exchange and subsequent H2 reduction. The prepared Pd@NH2-UiO-66 catalyst was then applied in the hydrodeoxygenation of vanillin (a typical model compound of lignin) at a low H2 pressure in aqueous media. Excellent catalytic results (100% conversion of vanillin with exclusive selectivity for 2-methoxy-4-methylphenol) could be achieved over the developed 2.0 wt% Pd@NH2-UiO-66 catalyst under mild conditions. Furthermore, the catalytic activity and selectivity were not affected after six reaction cycles indicating excellent stability and reproducibility of this catalyst system. It was found that the presence of free amine groups in the framework of NH2-UiO-66 plays a key role in the formation of uniform, well-dispersed and leaching resistant palladium nanoparticles within the MOF host. Moreover, the developed Pd@NH2-UiO-66 exhibits a novel synergetic catalysis in the hydrodeoxygenation due to the cooperation between the well-dispersed metallic Pd sites and the amine-functionalized MOF support, in which Pd offers hydrogenation activity and the MOF support facilitates hydrogenolysis of the intermediate vanillin alcohol to the 2-methoxy-4-methylphenol product.
Cooperative catalysis at the metal-MOF interface: Hydrodeoxygenation of vanillin over Pd nanoparticles covered with a UiO-66(Hf) MOF
Bakuru, Vasudeva Rao,Davis, Deljo,Kalidindi, Suresh Babu
, p. 8573 - 8577 (2019)
Cooperative catalysis has been demonstrated over metal-MOF hybrids for the conversion of vanillin (biomass based platform molecules) into value-added 2-methoxy-4-methylphenol. Over a Pd@UiO-66(Hf) core-shell catalyst, cooperativity between Br?nsted acidic μ3-OH groups and Pd active sites present at the interface has rendered a catalytic performance of >99% vanillin conversion and >99% 2-methoxy-4-methylphenol selectivity at 90 °C under 3 bar H2 in water. An enhanced cooperative effect has been observed over a core-shell catalyst compared to a support catalyst.
Autonomously Propelled Motors for Value-Added Product Synthesis and Purification
Srivastava, Sarvesh K.,Schmidt, Oliver G.
, p. 9072 - 9076 (2016)
A proof-of-concept design for autonomous, self-propelling motors towards value-added product synthesis and separation is presented. The hybrid motor design consists of two distinct functional blocks. The first, a sodium borohydride (NaBH4) granule, serves both as a reaction prerequisite for the reduction of vanillin and also as a localized solid-state fuel in the reaction mixture. The second capping functional block consisting of a graphene–polymer composite serves as a hydrophobic matrix to attract the reaction product vanillyl alcohol (VA), resulting in facile separation of this edible value-added product. These autonomously propelled motors were fabricated at a length scale down to 400 μm, and once introduced in the reaction environment showed rapid bubble-propulsion followed by high-purity separation of the reaction product (VA) by the virtue of the graphene–polymer cap acting as a mesoporous sponge. The concept has excellent potential towards the synthesis/isolation of industrially important compounds, affinity-based product separation, pollutant remediation (such as heavy metal chelation/adsorption), as well as localized fuel-gradients as an alternative to external fuel dependency.
Novel analogs of 5-hydroxymethyl-2-methoxyphenyl adamantane-1-acetate: synthesis, biotesting, and molecular modeling
Zefirov,Mamaeva,Krasnoperova,Evteeva, Yu. A.,Milaeva,Kuznetsov,Zefirova
, p. 549 - 554 (2021)
A series of novel analogs of dual-targeted antimitotic agent 5-hydroxymethyl-2-methoxyphenyl adamantane-1-acetate was synthesized. These compounds maintained the cytostatic ability of the lead molecule and induced no depolymerization of microtubules in human lung carcinoma cells A549. The importance of substituent positions in the aromatic ring for interactions with the microtubules was explained using computer molecular modeling.
Protective Effect of vanilloids against tert-butyl hydroperoxide-induced oxidative stress in vero cells culture
Rosa, Antonella,Atzeri, Angela,Deiana, Monica,Melis, M. Paola,Incani, Alessandra,Corona, Giulia,Loru, Debora,Appendino, Giovanni,Dessi, M. Assunta
, p. 3546 - 3553 (2008)
This study investigated the effect of synthetic capsiate, a simplified analogue of capsiate, and vanillyl alcohol on the oxidative stress induced by tert-butyl hydroperoxide (TBH) in a line of fibroblasts derived from monkey kidney (Vera cells). In response to the TBH-mediated oxidative stress, a reduction of the levels of total unsaturated fatty acids and cholesterol was observed, and a rise in the concentrations of conjugated dienes fatty acids hydroperoxides and 7-ketocholesterol. Pretreatment with both synthetic capsiate and vanillyl alcohol preserved Vero cells from oxidative damage and showed a remarkable protective effect on the reduction of the levels of total unsaturated fatty acids and cholesterol, inhibiting the increase of MDA, conjugated dienes fatty acids hydroperoxides, and 7-ketocholesterol. Both compounds were effective against peroxidation of cell membrane lipids induced by TBH, with synthetic capsiate essentially acting as a pro-drug of vanillyl alcohol, its hydrophilic hydrolytic derivative.
Pd Nanoparticles Supported on Cellulose as a Catalyst for Vanillin Conversion in Aqueous Media
Li, Dan-Dan,Zhang, Jia-Wei,Cai, Chun
, p. 7534 - 7538 (2018)
Palladium nanoparticles were first anchored on modified biopolymer as an efficient catalyst for a biofuel upgrade. Fluorinated compounds was grafted onto cellulose to obtain amphiphilic supports for on water reactions. Pd catalyst was prepared by straightforward deposition of metal nanoparticles on modified cellulose. The catalyst exhibited excellent catalytic activity and selectivity in hydrodeoxygenation of vanillin (a typical model compound of lignin) to 2-methoxy-4-methylphenol under atmospheric hydrogen pressure in neat water without any other additives under mild conditions.
Multi-Enzymatic Cascade Reactions for the Synthesis of cis,cis-Muconic Acid
Di Nardo, Giovanna,Gazzola, Silvia,Gilardi, Gianfranco,Pollegioni, Loredano,Rosini, Elena,Valetti, Francesca,Vignali, Elisa
supporting information, p. 114 - 123 (2021/10/07)
Lignin valorization allows the generation of a number of value-added products such as cis,cis-muconic acid (ccMA), which is widely used for the synthesis of chemicals for the production of biodegradable plastic materials. In the present work, we reported the first multi-enzymatic, one-pot bioconversion process of vanillin into ccMA. In details, we used four sequential reactions catalyzed by xanthine oxidase, O-demethylase LigM (and the tetrahydrofolate-regeneration enzyme methyl transferase MetE), decarboxylase AroY (based on the use of E. coli transformed cells) and catechol 1,2-dioxygenase CatA. The optimized lab-scale procedure allowed to reach, for the first time, the conversion of 5 mM vanillin into ccMA in ～30 h with a 90% yield: this achievement represents an improvement in terms of yields and time when compared to the use of a whole-cell system. This multi-enzymatic system represents a sustainable alternative for the production of a high value added product from a renewable resource. (Figure presented.).
Chemoselective Transfer Hydrogenation of Flavoring Unsaturated Carbonyl Compounds over Zr and Hf-based Metal–Organic Frameworks
Valekar, Anil H.,Oh, Kyung-Ryul,Hwang, Young Kyu
supporting information, p. 467 - 470 (2021/02/03)
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Deep eutectic solvents as H2-sources for Ru(II)-catalyzed transfer hydrogenation of carbonyl compounds under mild conditions
Cavallo, Marzia,Arnodo, Davide,Mannu, Alberto,Blangetti, Marco,Prandi, Cristina,Baratta, Walter,Baldino, Salvatore
supporting information, (2021/02/22)
The employment of easily affordable ruthenium(II)-complexes as pre-catalysts in the transfer hydrogenation of carbonyl compounds in deep eutectic media is described for the first time. The eutectic mixture tetrabutylammonium bromide/formic acid = 1/1 (TBABr/HCOOH = 1/1) acts both as reaction medium and hydrogen source. The addition of a base is required for the process to occur. An extensive optimization of the reaction conditions has been carried out, in terms of catalyst loading, type of complexes, H2-donors, reaction temperature and time. The combination of the dimeric complex [RuCl(p-cymene)-μ-Cl]2 (0.01–0.05 eq.) and the ligand dppf (1,1′-ferrocenediyl-bis(diphenylphosphine)ferrocene) in 1/1 molar ratio has proven to be a suitable catalytic system for the reduction of several and diverse aldehydes and ketones to their corresponding alcohols under mild conditions (40–60 °C) in air, showing from moderate to excellent tolerability towards different functional groups (halogen, cyano, nitro, phenol). The reduction of imine compounds to their corresponding amine derivatives was also studied. In addition, the comparison between the results obtained in TBABr/HCOOH and in organic solvents suggests a non-innocent effect of the DES medium during the process.
