Walter Johnsen grew up in New York City, NY. He completed his undergraduate degree at a Cornell University, where he received a B.A. in Chemistry and Chemical Biology and a minor in History. While at Cornell, Walter researched with Dr. Stephen Lee and Dr. Kyle Lancaster.

At Penn, Walter is advised by Dr. Tom Mallouk and Dr. Karen Goldberg. He is investigating the electrochemical reduction of carbon dioxide to multi-carbon products.

Outside of lab, Walter enjoys running, swimming, and hiking.