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 A Use-Store-Reuse (USR) Concept in Catalytic HCOOH Dehydrogenation: Case-Study of a Ru-Based Catalytic System for Long-Term USR under Ambient O2

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 481
Author(s):  
Marinos Theodorakopoulos ◽  
Maria Solakidou ◽  
Yiannis Deligiannakis ◽  
Maria Louloudi
Keyword(s):  
Catalytic System ◽  
Water System ◽  
Catalytic Efficiency ◽  
Ambient Air ◽  
Catalytic Performance ◽  
H2 Production ◽  
Repeated Use ◽  
Biphasic Catalytic System ◽  
First Time

Commercial use of H2 production catalysts requires a repeated use/stop/store and reuse of the catalyst. Ideally, this cycle should be possible under ambient O2. Herein we exemplify the concept of Use-Store-Reuse (USR) of a (Ru-phosphine) catalyst in a biphasic catalytic system, for H2 production via dehydrogenation of HCOOH. The catalytic system can operate uninterrupted for at least four weeks, including storage and reuse cycles, with negligible loss of its catalytic efficiency. The catalytic system consisted of a RuP(CH2CH2PPh2)3 (i.e. RuPP3) in (tri-glyme/water) system, using KOH as a cocatalyst, to promote HCOOH deprotonation. In a USR cycle of 1 week, followed by storage for three weeks under ambient air and reuse, the system achieved in total TONs > 90,000 and TOFs > 4000 h−1. Thus, for the first time, a USR concept with a readily available stable ruthenium catalyst is presented, operating without any protection from O2 or light, and able to retain its catalytic performance.

Lichens of the Oasis Molodyozhnyi and adjacent areas (Enderby Land, Antarctic)

2013 ◽  
Vol 47 ◽  
pp. 167-178 ◽  
Author(s):  
M. P. Andreev
Keyword(s):  
Liquid Water ◽  
Climate Conditions ◽  
Water Ice ◽  
Buellia Frigida ◽  
Antarctic Continent ◽  
Harsh Climate ◽  
The Antarctic ◽  
First Time ◽  
Lichen Flora

Lichen flora and vegetation in the vicinity of the Russian base «Molodyozhnaya» (Enderby Land, Antarctica) were investigated in 2010–2011 in details for the first time. About 500 specimens were collected in 100 localities in all available ecotopes. The lichen flora is the richest in the region and numbers 39 species (21 genera, 11 families). The studied vegetation is very poor and sparse, but typical for coastal oases of the Antarctic continent. The poorness is caused by the extremely harsh climate conditions, insufficient availability of liquid water, ice-free land, and high insolation levels. The dominant and most common lichens are Rinodina olivaceobrunnea, Amandinea punctata, Candelariella flava, Physcia caesia, Caloplaca tominii, Lecanora expectans, Caloplaca ammiospila, Lecidea cancriformis, Pseudephebe minuscula, Lecidella siplei, Umbilicaria decussata, Buellia frigida, Lecanora fuscobrunnea, Usnea sphacelata, Lepraria and Buellia spp.

scholarly journals Design, synthesis, and catalytic performance of modified graphene oxide based on a cobalt complex as a heterogenous catalyst for the preparation of aminonaphthoquinone derivatives

RSC Advances ◽  
2021 ◽  
Vol 11 (28) ◽  
pp. 17108-17115
Author(s):  
Mahnaz Mirheidari ◽  
Javad Safaei-Ghomi
Keyword(s):  
Graphene Oxide ◽  
Cobalt Complex ◽  
Catalytic Performance ◽  
Silica Particles ◽  
Design Synthesis ◽  
Spherical Silica ◽  
Modified Graphene Oxide ◽  
Spherical Silica Particles ◽  
Heterogenous Catalyst ◽  
Modified Graphene

GO@f-SiO2@Co is a heterogenous catalyst composed of spherical silica particles grafted on the surface of graphene oxide with ethylenediamine ligands and coordination with Co(ii). We assessed the activity of the catalyst for the synthesis of aminonaphthoquinones.

Ternary NiS/ZnxCd1-xS/Reduced Graphene Oxide Nanocomposites for Enhanced Solar Photocatalytic H2-Production Activity

2014 ◽  
Vol 4 (10) ◽  
pp. 1301925 ◽  
Author(s):  
Jun Zhang ◽  
Lifang Qi ◽  
Jingrun Ran ◽  
Jiaguo Yu ◽  
Shi Zhang Qiao
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
H2 Production ◽  
Reduced Graphene ◽  
Production Activity

Growth kinetic control over MgFe2O4 to tune Fe occupancy and metal–support interactions for optimum catalytic performance

CrystEngComm ◽  
2021 ◽  
Vol 23 (13) ◽  
pp. 2538-2546
Author(s):  
Min Yang ◽  
Guangshe Li ◽  
Huixia Li ◽  
Junfang Ding ◽  
Yan Wang ◽  
...  
Keyword(s):  
Co Oxidation ◽  
Growth Kinetic ◽  
Catalytic Performance ◽  
Growth Behavior ◽  
Kinetic Control ◽  
Size Dependent ◽  
Metal Support ◽  
Support Size ◽  
Metal Support Interactions ◽  
First Time

For the first time, the growth behavior with size-dependent Fe occupancies at different sites of MgFe2O4 was examined. Hybrid catalysts of Pt/MgFe2O4 with a support size of 20.6 nm exhibited an optimal performance of CO oxidation.

CsOH and its Lighter Homologues – a Comparison

2014 ◽  
Vol 69 (11-12) ◽  
pp. 1229-1236
Author(s):  
Matthias Wörsching ◽  
Constantin Hoch
Keyword(s):  
Gas Phase ◽  
Room Temperature ◽  
Structure Type ◽  
Alkali Metal Hydroxide ◽  
X Ray ◽  
Raman Spectroscopic ◽  
Cesium Hydroxide ◽  
Free Ion ◽  
The One ◽  
First Time

Abstract Cesium hydroxide, CsOH, was for the first time characterised on the basis of single-crystal data. The structure is isotypic to the one of the room-temperature modification of NaOH and can be derived from the NaCl structure type thus allowing the comparison of all alkali metal hydroxide structures. Raman spectroscopic investigations show the hydroxide anion to behave almost as a free ion as in the gas phase. The X-ray investigations indicate possible H atom positions.

Synthesis, Structure, and Catalytic Performance in Cyclooctene Epoxidation of a Molybdenum Oxide/Bipyridine Hybrid Material: {[MoO3(bipy)][MoO3(H2O)]}n

2010 ◽  
Vol 49 (15) ◽  
pp. 6865-6873 ◽  
Author(s):  
Marta Abrantes ◽  
Tatiana R. Amarante ◽  
Margarida M. Antunes ◽  
Sandra Gago ◽  
Filipe A. Almeida Paz ◽  
...  
Keyword(s):  
Molybdenum Oxide ◽  
Hybrid Material ◽  
Catalytic Performance ◽  
Cyclooctene Epoxidation
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