The development of efficient renewable energy conversion and storage devices is one of the most important challenges of the 21st century. Fuel cell catalysis, CO2 reduction, etc. are interesting reactions that can transform our energy economy; however, many of these reactions are sluggish from unfavorable reaction kinetics and poor product selectivity. These renewable energy technologies are rooted in interfacial electrochemistry in which reactions are catalyzed at electrified metal-solution interfaces. Controlling the properties of both the metal and electrolyte solution is paramount for achieving high performance electrocatalysis. This talk will discuss our recent efforts on the synthesis, stability, and catalytic activity of atomically well-defined alloys (ordered intermetallic compounds) prepared by an electrochemically induced phase transformation (EIPT) at room temperature. We also discuss how the catalytic reactivity of materials can be tuned by controlling the identity of the electrolyte. Developing fundamental insights into electrified metal-solution interfaces can provide knowledge essential for ushering in the next generation of renewable devices.