Stepwise production of syngas and hydrogen through methane reforming and water splitting by using a cerium oxide redox system

Abstract

Stepwise production of syngas and hydrogen from ZrO 2-supported CeO 2 through methane reforming and water splitting was investigated in order to find proper operating conditions under which carbon deposition could be minimized. Recommendable operating temperature and time were 1073 K and 30 min for both the methane reforming and the water splitting. Even though the H 2/CO ratio during the methane reforming was maintained close to the desired ratio of 2, undesirable methane cracking occurred to a small extent and further reduction of Ce 2O 3 to metallic Ce by CH 4 and H 2 occurred to some extent. When the methane reforming-water splitting cyclic operations were repeated, the yields of syngas and hydrogen decreased considerably from the first cycle to the second cycle, but from the second cycle to the fifth cycle the gas yields were maintained nearly constant. As the CeO 2 content in the sample increased, the gas yields per mole of CeO 2 decreased but the gas productions per gram of sample increased.