141-53-7Relevant articles and documents
Synthesis and reactivity of iron complexes with a new pyrazine-based pincer ligand, and application in catalytic low-pressure hydrogenation of carbon dioxide
Rivada-Wheelaghan, Orestes,Dauth, Alexander,Leitus, Gregory,Diskin-Posner, Yael,Milstein, David
, p. 4526 - 4538 (2015)
A novel pincer ligand based on the pyrazine backbone (PNzP) has been synthesized, (2,6-bis(di(tert-butyl)phosphinomethyl)pyrazine), tBu-PNzP. It reacts with FeBr2 to yield [Fe(Br)2(tBu-PNzP)], 1. Treatment of 1 with NaBH4 in MeCN/MeOH gives the hydride complex [Fe(H)(MeCN)2(tBu-PNzP)][X] (X = Br, BH4), 2·X. Counterion exchange and exposure to CO atmosphere yields the complex cis-[Fe(H)(CO)(MeCN)(tBu-PNzP)][BPh4] 4·BPh4, which upon addition of Bu4NCl forms [Fe(H)(Cl)(CO)(tBu-PNzP)] 5. Complex 5, under basic conditions, catalyzes the hydrogenation of CO2 to formate salts at low H2 pressure. Treatment of complex 5 with a base leads to aggregates, presumably of dearomatized species B, stabilized by bridging to another metal center by coordination of the nitrogen at the backbone of the pyrazine pincer ligand. Upon dissolution of compound B in EtOH the crystallographically characterized complex 7 is formed, comprised of six iron units forming a 6-membered ring. The dearomatized species can activate CO2 and H2 by metal-ligand cooperation (MLC), leading to complex 8, trans-[Fe(PNzPtBu-COO)(H)(CO)], and complex 9, trans-[Fe(H)2(CO)(tBu-PNzP)], respectively. Our results point at a very likely mechanism for CO2 hydrogenation involving MLC.
Iron-catalyzed hydrogenation of bicarbonates and carbon dioxide to formates
Zhu, Fengxiang,Zhu-Ge, Ling,Yang, Guangfu,Zhou, Shaolin
, p. 609 - 612 (2015)
The catalytic hydrogenation of carbon dioxide and bicarbonate to formate has been explored extensively. The vast majority of the known active catalyst systems are based on precious metals. Herein, we describe an effective, phosphine-free, airand moisture-
Selective reduction of CO2 to formate through bicarbonate reduction on metal electrodes: New insights gained from SG/TC mode of SECM
Sreekanth, Narayanaru,Phani, Kanala Lakshminarasimha
, p. 11143 - 11146 (2014)
We discovered using SECM of the electro-reduction of CO2 on a Au substrate in CO2-saturated KHCO3 solutions that (i) formate comes solely from the direct reduction of bicarbonate; and (ii) CO forms only from CO2 reduction (under low pH conditions) and at higher applied potentials. The results point to the possibility of the selective reduction of CO2 to the formate product.
Catena-Poly[disodium [[diformato-tricopper(II)]-di-μ3- formato-tetra-μ2-formato]]: A new mode of bridging between binuclear and mononuclear formate-copper(II) units
Golobic, Amalija,Malekovic, Martina,Segedin, Primoz
, p. m102-m104 (2006)
The novel title polymeric copper(II) complex, {Na2[Cu 3-(CHO2)8]}n, consists of sodium cations and infinite anionic chains, in which neutral dinuclear [Cu 2(O2CH)4] moieties alternate with dianionic [Cu(O2CH)4]2- units. Both metal-containing moieties are located on crystallographic inversion centers. The syn-syn bridging configuration between the mononuclear and dinuclear components yields a structure that is significantly more dense than the structures previously reported for mononuclear-dinuclear copper(II) carboxylates with syn-anti or anti-anti bridging modes.
Formaldehyde Electro-oxidation on Copper Metal and Copper-based Amorphous Alloys in Alkaline Media
Machida, Ken-ichi,Enyo, Michio
, p. 2043 - 2050 (1985)
Copper metal and copper-based amorphous alloys, a-Cu35Ti65 and a-Cu33Zr67, exhibit a very high and stable activity for the anodic HCHO oxidation in aqueous NaOH and Na2CO3.The oxidation current was atready observable at electrode potentials as low as 0.1 V (RHE) and, in particular, the HF-treated amorphous alloys gave high current densities around 40 mA cm-2 (apparent) at 0.2 V.Kinetic data, roughly first order both in HCHO and OH(1-) concentration, are in favour of the mechanism in which the oxidation proceeds via hydroxymethanolate ion (HOCH2O(1-)) formed from HCHO and OH(1-), producing HCOO(1-) and H2: This ion is readily oxidized on the copper metal or copper-based amorphous alloy electrodes.The Tafel slope was in general agreement with the reaction mechanism assuming a rate-determining one-electron transfer step.
Mesoporous Silica-Encaged Ultrafine Bimetallic Nanocatalysts for CO2 Hydrogenation to Formates
Sun, Qiming,Fu, Xinpu,Si, Rui,Wang, Chi-Hwa,Yan, Ning
, p. 5093 - 5097 (2019)
CO2 hydrogenation to formic acid/formate has been recognized as a key reaction to realizing the CO2-mediated hydrogen energy cycle. Herein, ultrafine and well-dispersed Pd?CoO nanoparticles (～1.8 nm) were encapsulated within mesoporous silica nanospheres (MSNs) via a facile one-pot ligand-protected synthesis strategy. The MSN-encaged bimetallic nanocatalysts exhibit excellent catalytic activity and stability for the formate production from CO2 hydrogenation, showing high turnover frequency value up to 1824 h?1 at 373 K, which is among the top-level reported for heterogeneous catalysts.
Molecular H2O promoted catalytic bicarbonate reduction with methanol into formate over Pd0.5Cu0.5/C under mild hydrothermal conditions
Wang, Xiaoguang,Yang, Yang,Zhong, Heng,Wang, Tianfu,Cheng, Jiong,Jin, Fangming
, p. 430 - 439 (2021)
Direct reduction of bicarbonate, a typical product of CO2 captured in alkaline solution, into value-added organics is one promising way to achieve a simplified and green CO2 capture and utilization process. In this work, a new strategy of bicarbonate reduction coupled with methanol oxidation into a dual formation of formate under mild hydrothermal conditions is reported. A 68% formate production efficiency based on the reductant methanol and nearly 100% selectivity of formate were obtained via a Pd0.5Cu0.5/C catalyst at 180 °C. An operando hydrothermal ATR-FTIR study proved that the bicarbonate was reduced by the in situ generated hydrogen from methanol, which was stepwise oxidized to formaldehyde and formic acid. Notably, DFT calculations and a qNMR study of the 13C and 2H (D) isotopic labelling revealed that H2O molecules not only supplied the hydrogen for bicarbonate reduction but also acted as an indispensable promoter to enhance the catalytic performance of Pd0.5Cu0.5/C for methanol activation.
A MOF-assisted phosphine free bifunctional iron complex for the hydrogenation of carbon dioxide, sodium bicarbonate and carbonate to formate
Coufourier, Sébastien,Gaillard, Sylvain,Clet, Guillaume,Serre, Christian,Daturi, Marco,Renaud, Jean-Luc
, p. 4977 - 4980 (2019)
The hydrogenation of carbon dioxide into formic acid (FA) with Earth-abundant metals is a vibrant research area because FA is an attractive molecule for hydrogen storage. We report a cyclopentadienyl iron tricarbonyl complex that provides up to 3000 turnover number for carbon dioxide hydrogenation when combined with a catalytic amount of the chromium dicarboxylate MOF MIL-53(Cr). To date, this is the highest turnover number reported in the presence of a phosphine-free iron complex.
An amino acid based system for CO2capture and catalytic utilization to produce formates
Wei, Duo,Junge, Henrik,Beller, Matthias
, p. 6020 - 6024 (2021)
Herein, we report a novel amino acid based reaction system for CO2 capture and utilization (CCU) to produce formates in the presence of the naturally occurring amino acid l-lysine. Utilizing a specific ruthenium-based catalyst system, hydrogenation of absorbed carbon dioxide occurs with high activity and excellent productivity. Noteworthy, following the CCU concept, CO2 can be captured from ambient air in the form of carbamates and converted directly to formates in one-pot (TON > 50?000). This protocol opens new potential for transforming captured CO2 from ambient air to C1-related products.
CO2 reduction with protons and electrons at a boron-based reaction center
Taylor, Jordan W.,McSkimming, Alex,Essex, Laura A.,Harman, W. Hill
, p. 9084 - 9090 (2019)
Borohydrides are widely used reducing agents in chemical synthesis and have emerging energy applications as hydrogen storage materials and reagents for the reduction of CO2. Unfortunately, the high energy cost associated with the multistep preparation of borohydrides starting from alkali metals precludes large scale implementation of these latter uses. One potential solution to this issue is the direct synthesis of borohydrides from the protonation of reduced boron compounds. We herein report reactions of the redox series [Au(B2P2)]n (n = +1, 0, -1) (B2P2, 9,10-bis(2-(diisopropylphosphino)phenyl)-9,10-dihydroboranthrene) and their conversion into corresponding mono- and diborohydride complexes. Crucially, the monoborohydride can be accessed via protonation of [Au(B2P2)]-, a masked borane dianion equivalent accessible at relatively mild potentials (-2.05 V vs. Fc/Fc+). This species reduces CO2 to produce the corresponding formate complex. Cleavage of the formate complex can be achieved by reduction (ca. -1.7 V vs. Fc/Fc+) or by the addition of electrophiles including H+. Additionally, direct reaction of [Au(B2P2)]- with CO2 results in reductive disproportion to release CO and generate a carbonate complex. Together, these reactions constitute a synthetic cycle for CO2 reduction at a boron-based reaction center that proceeds through a B-H unit generated via protonation of a reduced borane with weak organic acids.
