Co-catalytic Effect of Functionalized SiO2 Materials on H2 Production from Formic Acid by an Iron Catalyst

2014 ◽  
Vol 1641 ◽  
Author(s):  
Panagiota Stathi ◽  
Yiannis Deligiannakis ◽  
Maria Louloudi
Keyword(s):  
Formic Acid ◽  
Functional Groups ◽  
Catalytic Effect ◽  
Iron Catalyst ◽  
Active Catalyst ◽  
H2 Production ◽  
Remarkable Increase ◽  
Co Catalysts ◽  
Surface Modified

ABSTRACTSurface modified L@SiO2 particles bearing covalently attached functional groups (L) have been tested as co-catalysts for H2 production from Formic Acid (FA) by the homogenous FeII/P(CH2CH2PPh2)3 catalyst. The L@SiO2 particles induce remarkable increase of catalytic H2 production i.e. by 710 %, when L=a basic functionality such as Imidazoles, or NH2-groups. This effect is attributed to a thermodynamic promotion of FA deprotonation facilitating coordination of HCOO- anion on the FeII atom of active catalyst during catalysis.

scholarly journals From Homogeneous to Heterogenized Molecular Catalysts for H2 Production by Formic Acid Dehydrogenation: Mechanistic Aspects, Role of Additives, and Co-Catalysts

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 733 ◽  
Author(s):  
Panagiota Stathi ◽  
Maria Solakidou ◽  
Maria Louloudi ◽  
Yiannis Deligiannakis
Keyword(s):  
Formic Acid ◽  
Sodium Formate ◽  
H2 Production ◽  
Ambient Conditions ◽  
Co Catalysts ◽  
High Concentrations ◽  
Formic Acid Dehydrogenation ◽  
Key Steps ◽  
Molecular Catalysts

H2 production via dehydrogenation of formic acid (HCOOH, FA), sodium formate (HCOONa, SF), or their mixtures, at near-ambient conditions, T < 100 °C, P = 1 bar, is intensively pursued, in the context of the most economically and environmentally eligible technologies. Herein we discuss molecular catalysts (ML), consisting of a metal center (M, e.g., Ru, Ir, Fe, Co) and an appropriate ligand (L), which exemplify highly efficient Turnover Numbers (TONs) and Turnover Frequencies (TOFs) in H2 production from FA/SF. Typically, many of these ML catalysts require the presence of a cofactor that promotes their optimal cycling. Thus, we distinguish the concept of such cofactors in additives vs. co-catalysts: When used at high concentrations, that is stoichiometric amounts vs. the substrate (HCOONa, SF), the cofactors are sacrificial additives. In contrast, co-catalysts are used at much lower concentrations, that is at stoichiometric amount vs. the catalyst. The first part of the present review article discusses the mechanistic key steps and key controversies in the literature, taking into account theoretical modeling data. Then, in the second part, the role of additives and co-catalysts as well as the role of the solvent and the eventual inhibitory role of H2O are discussed in connection to the main mechanistic steps. For completeness, photons used as activators of ML catalysts are also discussed in the context of co-catalysts. In the third part, we discuss examples of promising hybrid nanocatalysts, consisting of a molecular catalyst ML attached on the surface of a nanoparticle. In the same context, we discuss nanoparticulate co-catalysts and hybrid co-catalysts, consisting of catalyst attached on the surface of a nanoparticle, and their role in the performance of molecular catalysts ML.

scholarly journals Electrochemical Evaluation of Surface Modified Free-Standing CNT Electrode for Li–O2 Battery Cathode

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4196
Author(s):  
Ji Hyeon Lee ◽  
Hyun Wook Jung ◽  
In Soo Kim ◽  
Min Park ◽  
Hyung-Seok Kim
Keyword(s):  
Functional Groups ◽  
Atomic Layer ◽  
Free Standing ◽  
Coating Technology ◽  
Oxygen Functional Groups ◽  
Layer Deposition ◽  
Discharge Product ◽  
Effect Of Oxygen ◽  
Surface Modified ◽  
Electrochemical Evaluation

In this study, carbon nanotubes (CNTs) were used as cathodes for lithium–oxygen (Li–O2) batteries to confirm the effect of oxygen functional groups present on the CNT surface on Li–O2 battery performance. A coating technology using atomic layer deposition was introduced to remove the oxygen functional groups present on the CNT surface, and ZnO without catalytic properties was adopted as a coating material to exclude the effect of catalytic reaction. An acid treatment process (H2SO4:HNO3 = 3:1) was conducted to increase the oxygen functional groups of the existing CNTs. Therefore, it was confirmed that ZnO@CNT with reduced oxygen functional groups lowered the charging overpotential by approximately 230 mV and increased the yield of Li2O2, a discharge product, by approximately 13%. Hence, we can conclude that the ZnO@CNT is suitable as a cathode material for Li–O2 batteries.

Chemical Modification of the Porous Silicon Surface

1994 ◽  
Vol 358 ◽  
Author(s):  
Eric J. Lee ◽  
James S. Ha ◽  
Michael J. Sailor
Keyword(s):  
Porous Silicon ◽  
Chemical Modification ◽  
Formic Acid ◽  
Gas Phase ◽  
Silicon Surface ◽  
Chemical Vapor ◽  
Luminescence Quenching ◽  
Porous Silicon Surface ◽  
Phase Water ◽  
Surface Modified

ABSTRACTThe porous silicon (PS) surface is derivatized with ethanol, triethylsilanol and formic acid as well as oxidized with water. The two reactions used to prepare these surfaces are discussed, and FTIR spectra of the products are presented. Surface-modified PS retains 10-40% of its original photoluminescence. PS-derivatives display reversible luminescence quenching by gas phase water, ethanol, acetonitrile and benzene. The extent of quenching varies with different PS-derivatives depending on the interaction of the chemical vapor with the modified PS surfaces.

scholarly journals Facile Deoxygenation of Hydroxylated Flavonoids by Palladium-Catalysed Reduction of its Triflate Derivatives

2005 ◽  
Vol 60 (7) ◽  
pp. 792-796 ◽  
Author(s):  
József Kövér ◽  
Sándor Antus
Keyword(s):  
Formic Acid ◽  
Functional Groups ◽  
Catalytic Amount ◽  
Palladium Acetate ◽  
Efficient Procedure ◽  
Related Compounds

An efficient procedure to deoxygenate hydroxy substituted flavonoids, isoflavonoids and related compounds via their trifluoromethanesulfonates is presented. Their reduction with formic acid in the presence of a catalytic amount of palladium acetate, triethylamine and 1,3-bis(diphenylphosphanyl) propane (dppp) in DMF results in their des-hydroxy derivatives without affecting other functional groups.

Pebax-1657 mixed matrix membrane containing surface modified multi-walled carbon nanotubes for gas separation

RSC Advances ◽  
2016 ◽  
Vol 6 (83) ◽  
pp. 79563-79577 ◽  
Author(s):  
S. A. Habibiannejad ◽  
A. Aroujalian ◽  
A. Raisi
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Functional Groups ◽  
Gas Separation ◽  
Mixed Matrix Membrane ◽  
Mixed Matrix ◽  
Multi Walled Carbon Nanotubes ◽  
Surface Modified ◽  
Walled Carbon Nanotubes

In this study different functional groups on the surface of carbon nanotube enhanced the performance of Pebax 1657/MWNTs.

scholarly journals Ionic-exchange immobilization of ultra-low loading palladium on a rGO electro-catalyst for high activity formic acid oxidation

RSC Advances ◽  
2018 ◽  
Vol 8 (33) ◽  
pp. 18619-18625 ◽  
Author(s):  
Jiuxiao Sun ◽  
Xingying Luo ◽  
Weiwei Cai ◽  
Jing Li ◽  
Zhao Liu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Formic Acid ◽  
High Activity ◽  
Functional Groups ◽  
Formic Acid Oxidation ◽  
Acid Oxidation ◽  
Ionic Exchange ◽  
Exchange Method

A formic acid oxidation electro-catalyst with ultra-low palladium (Pd) loading was prepared via an ionic exchange method by utilizing the acidic functional groups on graphene oxide (GO).

scholarly journals Highly Stable N-Doped Carbon-Supported Pd-Based Catalysts Prepared from Biomass Waste for H2 Production from Formic Acid

2020 ◽  
Vol 8 (39) ◽  
pp. 15030-15043 ◽  
Author(s):  
Jessica Chaparro-Garnica ◽  
Miriam Navlani-García ◽  
David Salinas-Torres ◽  
Emilia Morallón ◽  
Diego Cazorla-Amorós
Keyword(s):  
Formic Acid ◽  
H2 Production ◽  
Biomass Waste ◽  
Supported Pd
Sign in / Sign up

Export Citation Format

Share Document