Multiwalled carbon nanotubes (MWCNTs) and activated carbon (AC)-supported K (9 wt %)-promoted trimetallic Co (4.5 wt %)−Rh (1.5 wt %)−Mo(15 wt %) catalysts are used to study the long-term deactivation for continuous 720 h of higher alcohols synthesis (HAS). The fresh catalysts are extensively characterized in both oxide and sulfide phases, together with the spent catalysts. The catalysts are tested for the synthesis of higher alcohols from synthesis gas under similar conditions of 330 °C, 9.1 MPa (1320 psig), and 3.8 m3 (STP)/((kg of cat.)/h), using a H2:CO molar ratio of 1.25. The alkali-promoted trimetallic Co−Rh−Mo catalyst supported on MWCNTs has shown two different deactivation steps: loss of sulfur from the surface and sintering of the catalyst species located on the outer surfaces of the carbon nanotubes. After regeneration, the total activity recovery (∼10%) over this catalyst is close to the total activity loss during the first deactivation step. The percentage CO conversion decreased from 58% to...