The Netherlands Center for Multiscale Catalytic Energy Conversion (MCEC) is a multidisciplinary research program. Chemists, physicists and engineers from Utrecht University (UU; commissioner of the MCEC-program), Eindhoven University of Technology (TU/e) and the University of Twente (UT) join forces in this program, in order to address one of the grand challenges that our society faces today: sustainable energy conversion. MCEC is a so-called Gravitation Program, funded by the Dutch Ministry of Education, Culture and Science (OCW).