Biomimetic polydopamine catalyst with redox-activity for oxygen-promoted H2 production via aqueous formaldehyde reforming

2021 ◽  
Author(s):  
Leilei Du ◽  
Gang Wang ◽  
Xiaoqing Yan ◽  
Hisayoshi Kobayashi ◽  
Sha Li ◽  
...  
Keyword(s):  
H2 Production ◽  
Redox Activity ◽  
Co Catalyst ◽  
Catalytically Active ◽  
First Time ◽  
Aqueous Formaldehyde

We report for the first time that biomimetic polydopamine (PDA) nanoparticles are catalytically active for formaldehyde (HCHO) reforming into hydrogen (H2), where O2 acts as a co-catalyst. The catechol on...

Controlling the performance of a silver co-catalyst by a palladium core in TiO2-photocatalyzed alkyne semihydrogenation and H2 production

2021 ◽  
pp. 118331
Author(s):  
Shota Imai ◽  
Yasumi Kojima ◽  
Eri Fudo ◽  
Atsuhiro Tanaka ◽  
Hiroshi Kominami
Keyword(s):  
H2 Production ◽  
Co Catalyst

scholarly journals Microwave-Assisted Catalytic Synthesis of Bio-Based Copolymers from Waste Cooking Oil

2017 ◽  
Author(s):  
Mahrzadi Noureen Shahi ◽  
Muhammad Arshad ◽  
Aman Ullah
Keyword(s):  
Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Waste Cooking Oil ◽  
Attenuated Total Reflection ◽  
Fatty Acid Esters ◽  
Proton Nuclear Magnetic Resonance ◽  
Co Catalyst ◽  
Cooking Oil ◽  
First Time ◽  
Acid Esters

Solvent free copolymerization of epoxides derived from fatty acid esters of waste cooking oil with phthalic anhydride using (salen)CrIII Cl as catalyst and n-Bu4NCl/DMAP as co-catalyst was carried out for the first time under microwave irradiation, where reaction time was reduced from number of hours to minutes. The polyesters were obtained with molecular weight (Mw = 3084-6740 g/mol) and dispersity values (D = 1.18-1.92), when (salen)CrIII Cl/n-Bu4NCl was used as catalysts. While in case of DMAP as a co-catalyst, polyesters with improved molecular weight (Mw = 5537-6925 g/mol) and narrow dispersity values (D = 1.07-1.28) were obtained even at reduced concentrations of (salen)CrIII Cl and DMAP. The obtained products were characterized and evaluated by attenuated total reflection-fourier transform infrared spectroscopy (ATR-FTIR), proton nuclear magnetic resonance (1H-NMR) spectroscopy, gel permeation chromatography (GPC) and thermogravimetric analysis (TGA) Techniques.

scholarly journals Branch site bulge conformations in domain 6 determine functional sugar puckers in group II intron splicing

2019 ◽  
Vol 47 (21) ◽  
pp. 11430-11440 ◽  
Author(s):  
Raphael Plangger ◽  
Michael Andreas Juen ◽  
Thomas Philipp Hoernes ◽  
Felix Nußbaumer ◽  
Johannes Kremser ◽  
...  
Keyword(s):  
Secondary Structure ◽  
Conformational Dynamics ◽  
Group Ii Intron ◽  
Sugar Pucker ◽  
Branch Site ◽  
Exon Ligation ◽  
Catalytically Active ◽  
Group Ii ◽  
First Time ◽  
Ligation Step

Abstract Although group II intron ribozymes are intensively studied the question how structural dynamics affects splicing catalysis has remained elusive. We report for the first time that the group II intron domain 6 exists in a secondary structure equilibrium between a single- and a two-nucleotide bulge conformation, which is directly linked to a switch between sugar puckers of the branch site adenosine. Our study determined a functional sugar pucker equilibrium between the transesterification active C2′-endo conformation of the branch site adenosine in the 1nt bulge and an inactive C3′-endo state in the 2nt bulge fold, allowing the group II intron to switch its activity from the branching to the exon ligation step. Our detailed NMR spectroscopic investigation identified magnesium (II) ions and the branching reaction as regulators of the equilibrium populations. The tuneable secondary structure/sugar pucker equilibrium supports a conformational selection mechanism to up- and downregulate catalytically active and inactive states of the branch site adenosine to orchestrate the multi-step splicing process. The conformational dynamics of group II intron domain 6 is also proposed to be a key aspect for the directionality selection in reversible splicing.

scholarly journals Ultrathin Ni(ii)-based coordination polymer nanosheets as a co-catalyst for promoting photocatalytic H2-production

2019 ◽  
Vol 55 (46) ◽  
pp. 6499-6502 ◽  
Author(s):  
Zhi-Qiang Jiang ◽  
Xing-Liang Chen ◽  
Jin Lu ◽  
Yu-Feng Li ◽  
Tian Wen ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Coordination Polymer ◽  
Visible Light ◽  
H2 Production ◽  
Co Catalyst ◽  
Photocatalytic Hydrogen Production ◽  
Co Catalysts ◽  
Production Activity ◽  
Visible Light Photocatalytic

The Ni(ii) coordination polymer nanosheets were successfully exfoliated, which can be used as co-catalysts (Ni-CPNS@CdS). The optimized Ni-CPNS@CdS catalyst showed a super high visible-light photocatalytic hydrogen production activity.

scholarly journals Fluorine-Substituted Arylphosphine for an NHC-Ni(I) System, Air-Stable in a Solid State but Catalytically Active in Solution

Molecules ◽  
2019 ◽  
Vol 24 (18) ◽  
pp. 3222 ◽  
Author(s):  
Matsubara ◽  
Fujii ◽  
Hosokawa ◽  
Inatomi ◽  
Yamada ◽  
...  
Keyword(s):  
Solid State ◽  
High Catalytic Activity ◽  
X Ray Diffraction ◽  
Aryl Bromides ◽  
Solid State Stability ◽  
Catalytically Active ◽  
Triphenylphosphine Complex ◽  
Oxidation In Air ◽  
Monovalent Nickel ◽  
First Time

Monovalent NHC-nickel complexes bearing triarylphosphine, in which fluorine is incorporated onto the aryl groups, have been synthesized. Tris(3,5-di(trifluoromethyl)-phenyl)phosphine efficiently gave a monovalent nickel bromide complex, whose structure was determined by X-ray diffraction analysis for the first time. In the solid state, the Ni(I) complex was less susceptible to oxidation in air than the triphenylphosphine complex, indicating greatly improved solid-state stability. In contrast, the Ni(I) complex in solution can easily liberate the phosphine, high catalytic activity toward the Kumada–Tamao–Corriu coupling of aryl bromides.

Metallic MoN ultrathin nanosheets boosting high performance photocatalytic H2production

2018 ◽  
Vol 6 (46) ◽  
pp. 23278-23282 ◽  
Author(s):  
Jingrun Ran ◽  
Hailong Wang ◽  
Huanyu Jin ◽  
Chongyi Ling ◽  
Xuliang Zhang ◽  
...  
Keyword(s):  
High Performance ◽  
Co Catalyst ◽  
Ultrathin Nanosheets ◽  
Highly Active ◽  
First Time

MoN nanosheets for the first time serve as a highly active co-catalyst to greatly enhance the photocatalytic H2production of TiO2.

scholarly journals Enhanced Photocatalytic Activity and Stability in Hydrogen Evolution of Mo6 Iodide Clusters Supported on Graphene Oxide

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1259
Author(s):  
Marta Puche ◽  
Rocío García-Aboal ◽  
Maxim A. Mikhaylov ◽  
Maxim N. Sokolov ◽  
Pedro Atienzar ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Gas Phase ◽  
Hybrid Material ◽  
Liquid Water ◽  
Catalytic Performance ◽  
H2 Production ◽  
Cluster Compound ◽  
Catalytic Systems ◽  
Active Cluster ◽  
First Time

Catalytic properties of the cluster compound (TBA)2[Mo6Ii8(O2CCH3)a6] (TBA = tetrabutylammonium) and a new hybrid material (TBA)2Mo6Ii8@GO (GO = graphene oxide) in water photoreduction into molecular hydrogen were investigated. New hybrid material (TBA)2Mo6Ii8@GO was prepared by coordinative immobilization of the (TBA)2[Mo6Ii8(O2CCH3)a6] onto GO sheets and characterized by spectroscopic, analytical, and morphological techniques. Liquid and, for the first time, gas phase conditions were chosen for catalytic experiments under UV–Vis irradiation. In liquid water, optimal H2 production yields were obtained after using (TBA)2[Mo6Ii8(O2CCH3)a6] and (TBA)2Mo6Ii8@GO) catalysts after 5 h of irradiation of liquid water. Despite these remarkable catalytic performances, “liquid-phase” catalytic systems have serious drawbacks: the cluster anion evolves to less active cluster species with partial hydrolytic decomposition, and the nanocomposite completely decays in the process. Vapor water photoreduction showed lower catalytic performance but offers more advantages in terms of cluster stability, even after longer radiation exposure times and recyclability of both catalysts. The turnover frequency (TOF) of (TBA)2Mo6Ii8@GO is three times higher than that of the microcrystalline (TBA)2[Mo6Ii8(O2CCH3)a6], in agreement with the better accessibility of catalytic cluster sites for water molecules in the gas phase. This bodes well for the possibility of creating {Mo6I8}4+-based materials as catalysts in hydrogen production technology from water vapor.

scholarly journals Enhanced Photocatalytic Hydrogen Production of the Polyoxoniobate Modified with RGO and PPy

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2449
Author(s):  
Shiliang Heng ◽  
Lei Li ◽  
Weiwei Li ◽  
Haiyan Li ◽  
Jingyu Pang ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Active Sites ◽  
High Efficiency ◽  
Solvothermal Method ◽  
H2 Production ◽  
H2 Evolution ◽  
Co Catalyst ◽  
Photocatalytic Hydrogen Production ◽  
Reduced Graphene ◽  
One Step

The development of high-efficiency, recyclable, and inexpensive photocatalysts for water splitting for hydrogen production is of great significance to the application of solar energy. Herein, a series of graphene-decorated polyoxoniobate photocatalysts Nb6/PPy-RGO (Nb6 = K7HNb6O19, RGO = reduced graphene oxide, PPy = polypyrrole), with the bridging effect of polypyrrole were prepared through a simple one-step solvothermal method, which is the first example of polyoxoniobate-graphene-based nanocomposites. The as-fabricated photocatalyst showed a photocatalytic H2 evolution activity without any co-catalyst. The rate of 1038 µmol g−1 in 5 h under optimal condition is almost 43 times higher than that of pure K7HNb6O19·13H2O. The influencing factors for photocatalysts in photocatalytic hydrogen production under simulated sunlight were studied in detail and the feasible mechanism is presented in this paper. These results demonstrate that Nb6O19 acts as the main catalyst and electron donor, RGO provides active sites, and PPy acted as an electronic bridge to extend the lifetime of photo-generated carriers, which are crucial factors for photocatalytic H2 production.

Near-infrared-activated NaYF4:Yb3+, Er3+/Au/CdS for H2 production via photoreforming of bio-ethanol: plasmonic Au as light nanoantenna, energy relay, electron sink and co-catalyst

2017 ◽  
Vol 5 (21) ◽  
pp. 10311-10320 ◽  
Author(s):  
Wenhui Feng ◽  
Lulu Zhang ◽  
Yan Zhang ◽  
Yu Yang ◽  
Zhibin Fang ◽  
...  
Keyword(s):  
Near Infrared ◽  
H2 Production ◽  
Light Irradiation ◽  
Low Density ◽  
Co Catalyst ◽  
Ethanol Reforming ◽  
Nir Light ◽  
Electron Sink

A sandwich-structured NaYF4:Yb3+, Er3+/Au/CdS architecture delivers enhanced photocatalytic bio-ethanol reforming activity under low-density NIR light irradiation.

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