Rolf Willestofte Berg

The present report demonstrates a one-step co-electrolysis of water and carbon dioxide in the vapor phase catalyzed by iron-based compounds to form C1 to C5 hydrocarbons. The medium-temperature electrolyzer works at 240 °C and 28 bar overpressure; the solid electrolyte consists of CsH2PO4 with polyvinyl butyral (PVB) as binder. The cathode is a porous platinum electrode followed by a layer of iron/Fischer-Tropsch catalysts sandwiched between Fe foams. The anode consists of tantalum coated steel felt covered by RuO2. Both electrodes are in contact with the electrolyte. Current densities of up to 200 mA/cm2 with a voltage of up to 2.2 volts were applied. The product selectivity and Faradaic efficiencies, together with the detailed analysis of the structure of the catalyst before and after use, show thermal Fischer-Tropsch catalysis parallel to electrolysis. Initially formed CO, in conjunction with high amounts of electrochemically produced hydrogen, reacts to form the hydrocarbons. The mechanistic conclusions are in agreement with the catalytic properties of metallic iron, iron carbide and iron oxide nanoparticles identified in the spent catalysts.

It has been shown that methane can be formed in high amounts by co-electrolysis of CO ₂ and H ₂ O using a nickel cathode, a CsH ₂ PO ₄ –SiC composite electrolyte and an IrO ₂ anode. The experimental conditions were 300 °C and 8 bar. The maximum efficiency close to 100% for methane was obtained at a current density of 10–15 mA cm ⁻² . A small amount of hydrogen was formed as the only other product.

The common substance Hydrohalite has a role to play in as diverse areas as Geology, Earth Climatology, Universe Cosmology, and Cryobiology. In this review, the occurrences under very different occasions are described. These relations are not commonly appreciated. During the work, we realized that there is yet an aspect that has been overlooked. Hydrohalite formed sometimes on icy roads resists common salt deicing procedures. Also, hydrohalite can be detected by rather simple Raman spectroscopy instrumentation. It means that it is possible to avoid accidents on icy roads in the following way: Common salt deicing trucks may be equipped with “artificial intelligence” based on a duel deicing system that switches between normal NaCl deicing and non-NaCl deicing based on Raman spectroscopy. The advantages are first of all less traffic accidents and lower environmental impact and corrosion from NaCl, but disadvantages are increased costs of investments and consumption of non-NaCl deicing agents.

The iminodisulfonate, [N(SO₃)₂]^3–, and phosphinodisulfonate, [P(SO₃)₂]^3–, ions have been investigated by performing ab initio MP2/6-311+G** calculations. The nitrogen and phosphorus atoms as part of the ions are shown to be divalent with a negative charge and two lone pairs on the nitrogen and phosphorus atoms. The experimentally known calcium sodium iminodisulfonate trihydrate and the analogous unknown compound calcium sodium phosphinodisulfonate trihydrate have also been investigated using the MP2/6-311+G** calculations. For the nitrogen compound, only minor changes occur in the iminodisulfonate ion when it becomes part of the calcium sodium iminodisulfonate trihydrate. For the phosphorus compound, the geometry of the phosphinodisulfonate ion changes significantly as part of calcium sodium phosphinodisulfonate trihydrate. Furthermore, the charges associated with the atoms in calcium sodium phosphinodisulfonate trihydrate are quite different from those of the phosphinodisulfonate ion. For calcium sodium iminodisulfonate trihydrate, the Raman spectrum has been measured, and it compares well with the spectrum derived using HF/6-311+G** calculations.