A Cs- and Pd-promoted Zn/Cr spinel (excess ZnO) higher alcohol synthesis (HAS) catalyst has been tested for the production of isobutanol and methane. An isobutanol production rate of 170 g/(kg h) and a methanol-to-isobutanol mole ratio of 0.44 are attained at 440 degrees C and 1000 psig. This ratio is lower than the desired value of 1.0 for MTBE production. Operating the reactor at a higher pressure of 1500 psig results in a lower isobutanol production rate of 161 g/(kg h) and an increased alcohol ratio of 0.7. A methanol-to-isobutanol mole ratio of 0.75 is also achieved under these operating conditions. These results are superior to others presented in the literature thus far. Surface characterization data indicate that the near-surface region of the catalyst consists primarily of ZnO and Cs. Pretreating the catalyst in a reductive environment similar to that given to the catalyst before reaction tests, causes an enrichment of the Cs promoter at the surface. The product stream composition does not significantly change after 5 days of testing. During this time, however, the amount of Cs relative to Zn measured by XPS at the surface decreases possibly by agglomeration. The Zn remains in a ZnO state after the reductive pretreatment and after removal from the reactor.