Efficient Solar-Driven Synthesis, Carbon Capture, and Desalinization, STEP: Solar Thermal Electrochemical Production of Fuels, Metals, Bleach

Adv Mater. 2011 Dec 15;23(47):5592-612. doi: 10.1002/adma.201103198. Epub 2011 Oct 25.


STEP (solar thermal electrochemical production) theory is derived and experimentally verified for the electrosynthesis of energetic molecules at solar energy efficiency greater than any photovoltaic conversion efficiency. In STEP the efficient formation of metals, fuels, chlorine, and carbon capture is driven by solar thermal heated endothermic electrolyses of concentrated reactants occuring at a voltage below that of the room temperature energy stored in the products. One example is CO(2) , which is reduced to either fuels or storable carbon at a solar efficiency of over 50% due to a synergy of efficient solar thermal absorption and electrochemical conversion at high temperature and reactant concentration. CO(2) -free production of iron by STEP, from iron ore, occurs via Fe(III) in molten carbonate. Water is efficiently split to hydrogen by molten hydroxide electrolysis, and chlorine, sodium, and magnesium from molten chlorides. A pathway is provided for the STEP decrease of atmospheric carbon dioxide levels to pre-industial age levels in 10 years.

MeSH terms

  • Air Pollution / economics
  • Air Pollution / prevention & control
  • Biofuels*
  • Carbon / chemistry*
  • Carbon Dioxide / chemistry
  • Carbon Dioxide / isolation & purification
  • Electrochemistry
  • Electrolysis
  • Ferric Compounds / chemistry
  • Hydrogen / chemistry
  • Iron / chemistry
  • Metals / chemistry*
  • Photochemical Processes
  • Sodium Chloride / chemistry
  • Sodium Chloride / isolation & purification*
  • Sodium Hypochlorite / chemistry*
  • Solar Energy / economics
  • Solar Energy / statistics & numerical data*
  • Temperature
  • Water / chemistry


  • Biofuels
  • Ferric Compounds
  • Metals
  • Water
  • Carbon Dioxide
  • Sodium Chloride
  • Carbon
  • Hydrogen
  • Sodium Hypochlorite
  • Iron