Colloid and nanosized catalysts in organic synthesis: IX. Hydrogenation of enamines with hydrogen at atmospheric pressure

2014 ◽  
Vol 84 (11) ◽  
pp. 2073-2075 ◽  
Author(s):  
V. M. Mokhov ◽  
Yu. V. Popov ◽  
D. N. Nebykov
Keyword(s):  
Organic Synthesis ◽  
Atmospheric Pressure ◽  
Nanosized Catalysts

Colloidal and Nanosized Catalysts in Organic Synthesis: XX. Continuous Hydrogenation of Imines and Enamines Catalyzed by Nickel Nanoparticles

2018 ◽  
Vol 88 (10) ◽  
pp. 2035-2038 ◽  
Author(s):  
Yu. V. Popov ◽  
V. M. Mokhov ◽  
S. E. Latyshova ◽  
D. N. Nebykov ◽  
A. O. Panov ◽  
...  
Keyword(s):  
Organic Synthesis ◽  
Nickel Nanoparticles ◽  
Nanosized Catalysts ◽  
Continuous Hydrogenation

scholarly journals Possible mechanisms of CO 2 reduction by H 2 via prebiotic vectorial electrochemistry

2019 ◽  
Vol 9 (6) ◽  
pp. 20190073 ◽  
Author(s):  
Rafaela Vasiliadou ◽  
Nikolay Dimov ◽  
Nicolas Szita ◽  
Sean F. Jordan ◽  
Nick Lane
Keyword(s):  
Organic Synthesis ◽  
Atmospheric Pressure ◽  
High Flux ◽  
Redox Potentials ◽  
Hydrothermal Conditions ◽  
Ph Gradients ◽  
The Poor ◽  
Membrane Bound ◽  
The Origin Of Life ◽  
Energy Converting

Methanogens are putatively ancestral autotrophs that reduce CO 2 with H 2 to form biomass using a membrane-bound, proton-motive Fe(Ni)S protein called the energy-converting hydrogenase (Ech). At the origin of life, geologically sustained H + gradients across inorganic barriers containing Fe(Ni)S minerals could theoretically have driven CO 2 reduction by H 2 through vectorial chemistry in a similar way to Ech. pH modulation of the redox potentials of H 2 , CO 2 and Fe(Ni)S minerals could in principle enable an otherwise endergonic reaction. Here, we analyse whether vectorial electrochemistry can facilitate the reduction of CO 2 by H 2 under alkaline hydrothermal conditions using a microfluidic reactor. We present pilot data showing that steep pH gradients of approximately 5 pH units can be sustained over greater than 5 h across Fe(Ni)S barriers, with H + -flux across the barrier about two million-fold faster than OH – -flux. This high flux produces a calculated 3-pH unit-gradient (equating to 180 mV) across single approximately 25-nm Fe(Ni)S nanocrystals, which is close to that required to reduce CO 2 . However, the poor solubility of H 2 at atmospheric pressure limits CO 2 reduction by H 2 , explaining why organic synthesis has so far proved elusive in our reactor. Higher H 2 concentration will be needed in future to facilitate CO 2 reduction through prebiotic vectorial electrochemistry.

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