Dr. Holbrook is a materials scientist by training (University of Cincinnati, BS, and Stanford University, MS and Ph.D.) and had a nearly 30-year career with Sandia National Laboratory Livermore, Battelle Columbus Labs, and the Pacific Northwest National Laboratory.

Holbrook retired from PNNL in 2006, and has been devoting all his efforts to promoting anhydrous ammonia as a zero-emission, sustainable fuel for mobile and stationary applications. Holbrook is Co-Chair of the Ammonia Fuel Network, an international group of technical and business representatives who are working to support the advancement of ammonia fuel, and the inventor of the solid state ammonia synthesis(SSAS) process.