Catalyst layers and electrolyzers

An electrolyzer comprising a catalyst layer comprising a catalytically active element interspersed with an ion conducting polymer,

• wherein said catalytic active element is selected from the group consisting of V, Cr, Mn, Fe, Co, Ni, Cu, Sn, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W, Re, Ir, Pt, Au, Hg, Al, Si, In, Tl, Pb, Bi, Sb, Te, U, Sm, Tb, La, Ce, and Nd;
• and
• wherein said ion conducting polymer comprises:
• a terpolymer of styrene, vinylbenzyl-Rs wherein Rs is a positively charged cyclic amine group, and vinylbenzyl-Rx, wherein Rx is at least one constituent selected from the group consisting of Cl, OH, and a reaction product between an OH or Cl and a reactant other than an amine, and wherein the total weight of the vinylbenzyl-Rx groups is at least 1% of the total weight of the terpolymer,
• the electrolyzer having a reactant stream input, wherein the reactant stream to the electrolyzer comprises at least one of CO2 or H2O.