A method for preparing a catalyst comprising the steps of: providing a gold-silver alloy article, removing the silver from the article by immersing the article in a de-alloying solution to form a nanoporous gold (NPG) article with a plurality of nanopores followed by cleaning the surface of the NPG article and removing the de-alloying solution from the nanopores with deionized water. An electrode is attached to the NPG article and a monoatomic layer/lower layer of copper, silver, or lead, is deposited onto the surface of and within the nanopores of the NPG article by immersing the NPG article in an ion solution to form an M-NPG article. The M-NPG article is removed from the ion solution and the monoatomic/lower layer is replaced with platinum ions by immersing the M-NPG article into a platinum ion solution followed by cleaning the electrode and the NPG-Pt article with deionized water. A monoatomic layer/lower layer of copper, silver, or lead, is then deposited onto the surface of and within the nanopores of the NPG-Pt article by immersing the NPG-Pt article in an ion solution to form an M-NPG-Pt article. The M-NPG-Pt article is removed from the ion solution and the monoatomic/lower layer of copper, silver, or lead is replaced with gold ions by immersing the M-NPG-Pt article into a gold ion solution to form an NPG-Pt--Au article followed by cleaning the electrode and the NPG-Pt--Au article with deionized water.