Welcome to the 23rd World Hydrogen Energy Conference (WHEC2020) held from 5-9 July 2020 in Istanbul, Turkey. Fossil fuels (i.e., petroleum, natural gas and coal), which meet most of the world’s energy demand today, are being depleted fast. Also, their combustion products are causing the global problems, such as the global warming, climate change, ozone layer depletion, acid rains, oxygen depletion and pollution, which are posing great danger for our environment and eventually for the life in our planet.