A catalytic reactor system especially useful for hydrogenation, dehydrogenation, hydrocarbon isomerization, and hydrocracking was demonstrated for isomerizing 1-butene to 2-butene. The reactor system includes a noble metal-containing catalyst bed and a base-metal catalyst bed in physical contact with but substantially unmixed with the noble metal catalyst bed. The reactor includes a gas inlet for sending hydrogen to the noble metal catalyst and an inlet for sending 1-butene to the second catalyst bed. An outlet is provided for product and unreacted hydrogen and 1-butene. The reactor system is configured such that hydrogen flows through the noble metal catalyst bed first and then through the base-metal catalyst bed, while 1-butene flows through the base metal catalyst bed, with minimal backflow through noble metal bed.
 This invention was made with government support under Contract No. W-7405-ENG-36 awarded by the U.S. Department of Energy to The Regents of the University of California. The government has certain rights in the invention.