Advanced catalytic materials play an enabling role in producing renewable fuels and chemicals from biomass, thereby helping meet the global climate-change goals set forth by the Intergovernmental Panel on Climate Change. Herein, we present a multiscale approach to accelerate the catalyst-process development cycle for catalytic fast pyrolysis (CFP) of biomass over Mo 2 C. Mo 2 C has been shown to possess co-localized acidic and metallic sites and exhibit high activity for deoxygenation of biomass pyrolysis model compounds. However, critical knowledge gaps remain regarding the effectiveness of this catalyst for CFP of whole biomass. We address these knowledge gaps and demonstrate that Mo 2 C is effective at deoxygenating biomass-pyrolysis products in the presence of H 2 but that it undergoes rapid selective and non-selective deactivation. The knowledge gaps addressed from this integrated study, targeting appropriate experiments across scales and feed types, enabled identification of critical modifications for advancing the CFP catalyst-process development cycle. • A multiscale evaluation of Mo 2 C for biomass catalytic fast pyrolysis is performed • Mo 2 C exhibits both selective and non-selective deactivation with whole biomass • Process and catalyst modifications are proposed for reducing deactivation • Model compound studies are essential but insufficient at predicting performance Catalytic fast pyrolysis (CFP) of biomass is an attractive process for producing bio-oils that can be further refined into fuels and chemicals, thus helping to reduce greenhouse-gas emissions. To meet the emissions reduction goals set forth by the Intergovernmental Panel on Climate Change, catalysts and processes for generating renewable products need to be rapidly designed and developed, calling for an accelerated catalyst-process development timeline. However, in the case of CFP, biomass pyrolysis produces a complex stream involving hundreds of molecules with multifunctional groups, steam, and metal impurities, which makes catalyst design challenging. This integrated study on biomass CFP over a promising multifunctional catalyst, Mo 2 C, addresses knowledge gaps critical to accelerating development of this catalyst and process. The intended outcome is to share lessons learned toward accelerating catalyst-process development cycles for systems with similar complex reaction chemistries. Accelerating the catalyst-process development cycle for complex chemistries, especially biomass processing, requires multiscale studies spanning model compound experiments to integrated, bench-scale tests with realistic feedstocks.