Patent ID: 7938890

Claim:
A system comprising: a cathodic component and an anodic component with a region between them; and a layered structure in the region between the cathodic component and the anodic component; the cathodic component, anodic component, and layered structure being configured such that, with oxygen and carbon dioxide at the cathodic component and hydrogen-containing molecules that can provide protons at the anodic component, reactions occur at the cathodic component producing carbon-containing ions, the carbon-containing ions are transported from the cathodic component to the anodic component, and reactions occur at the anodic component producing carbon dioxide; the layered structure including three or more layers in order between the cathodic and anodic components, the layers including: adjacent the cathodic and anodic components, respective cathode-side and anode-side layers; and between the cathode-side and anode-side layers, one or more buffering group layers, each including pH buffering groups; the pH buffering groups being segregated in the pH buffering group layers so that they do not travel into the anode-side and cathode-side layers; the buffering group layers containing sufficient pH buffering groups to reduce ionic current density of at least one of protons between the anodic component and the cathodic component and hydroxyl ions between the cathodic component and the anodic component, relative to ionic current density of the carbon-containing ions, the pH buffering groups permitting the transport of the carbon-containing ions between the cathodic component and the anodic component.