CO2 electroreduction favors carbon isotope 12C over 13C and facilitates isotope separation

Asymmetric autocatalysis triggered by carbon isotope (13C/12C) chirality.

Many apparently achiral organic molecules on Earth may be chiral because of random substitution of the 1.11% naturally abundant 13C for 12C in an enantiotopic moiety within the structure. However, chirality from this source is experimentally difficult to discern because of the very small difference between 13C and 12C. We have demonstrated that this small difference can be amplified to an easil...

Isotope Effects, Isotope Separation and Isotope Fractionation

Electrochemical isotope effect and lithium isotope separation.

A large electrochemical isotopic effect is observed upon the electrodeposition of lithium from solutions of propylene carbonate producing isotopically light metal deposits. The magnitude of fractionation is controlled by the applied overpotential and is largest close to equilibrium. Calculated partition function ratios for tetrahedrally coordinated lithium complexes and metallic lithium predict...

Applications of cavity ring-down spectroscopy to high precision isotope ratio measurement of 13C/12C in carbon dioxide.

Recent measurements of carbon isotopes in carbon dioxide using near-infrared, diode-laser-based cavity ring-down spectroscopy (CRDS) are presented. The CRDS system achieved good precision, often better than 0.2 per thousand, for 4% CO2 concentrations, and also achieved 0.15-0.25 per thousand precision in a 78 min measurement time with cryotrap-based pre-concentration of ambient CO2 concentratio...

High-precision optical measurements of 13C/12C isotope ratios in organic compounds at natural abundance.

A continuous-flow cavity ring-down spectroscopy (CRDS) system integrating a chromatographic separation technique, a catalytic combustor, and an isotopic (13)C/(12)C optical analyzer is described for the isotopic analysis of a mixture of organic compounds. A demonstration of its potential is made for the geochemically important class of short-chain hydrocarbons. The system proved to be linear ov...