Improved catalytic performance and corrosion resistance of selective laser melted 316L SS in a direct methanol fuel cell by surface anodization

The cellular microstructure is a special phenomenon in many additively manufactured metals and alloys. This work provided a new way to achieve both high catalytic performance and superior corrosion resistance for additively manufactured 316L stainless steel by surface engineering. Results show that a well-organized cellular structure array is formed along the sub-grain boundary during the anodization process and an oxidation voltage of 15 V afforded the selective laser melted 316L (SLM 316L-A15) with the largest specific surface area. Compared with the traditional 316L plate, the SLM 316L-A15 plate deserves a superior corrosion resistance due to the enrichment of molybdenum and chromium at the sub-grain boundary. The SLM 316L-A15 plate surface loaded with Pt nanoparticles exhibited excellent catalytic effect, which is ascribed to the increased electrochemical surface area and the beneficial synergistic effect between iron/chromium oxide and platinum.