Direct Conversion of Syngas to Higher Alcohols via Tandem Integration of Fischer–Tropsch Synthesis and Reductive Hydroformylation

Abstract

The selective conversion of syngas to higher alcohols is an attractive albeit elusive route in the quest for effective production of chemicals from alternative carbon resources. We report the tandem integration of solid cobalt Fischer-Tropsch and molecular hydroformylation catalysts in a one-pot slurry-phase process. Unprecedented selectivities (> 50 wt %) to C 2 + alcohols are achieved at CO conversion levels > 70 %, alongside negligible CO 2 side-production. The efficient overall transformation is enabled by catalyst engineering, bridging gaps in operation temperature and intrinsic selectivity which have classically precluded integration of these reactions in a single conversion step. Swift capture of 1olefin Fischer-Tropsch primary products by the molecular hydroformylation catalyst, presumably within the pores of the solid catalyst is key for high alcohol selectivity. The results underscore that controlled cooperation between solid aggregate and soluble molecular metal catalysts, which pertain to traditionally dichotomic realms of heterogeneous and homogeneous catalysis, is a promising blueprint toward selective conversion processes.

Advances in Selectivity Control for Fischer–Tropsch Synthesis to Fuels and Chemicals with High Carbon Efficiency

“…According to the number of metal types involved in the active phase, HAS catalysts can be briefly classified into monometallic and bimetallic active sites. Herein, we mainly discuss the significant advances in monometallic and bimetallic active sites as well as emerging multifunctional catalytic systems. − Typical catalytic performances over various typical active sites are summarized in Table S3.…”

“…Another type of multifunctional catalyst is composed of a modified FTS component and an olefin hydroformylation component via tandem catalysis. , The key idea is to transform the coproduced olefins into oxygenates, thus enhancing the total selectivity of HA products. Li et al reported a tandem catalyst composed of activated carbon-supported CoMn and Rh-metalated 3v-PPh 3 -based porous organic polymers (CoMn/MAC|Rh/3v-PPh 3 @POPs) that exhibited excellent oxygenate selectivity (62.7%) with the percentage of C 2+ OH and C 6+ OH over 96.6% and 70.7%, respectively .…”

“…The as-obtained olefins could further undergo a heterogeneous hydroformylation reaction with unreacted syngas to form aldehydes over the atomically dispersed Rh–P complex sites (Figure a). Very recently, Jeske et al reported that tandem integration of a heterogeneous metallic Co-based NP (NaPr–CoRu/AOmM) FTO catalyst and a homogeneously Co-based molecular olefin hydroformylation catalyst (Co 2 CO 8 +PCy 3 ) in a batch reactor can achieve an unprecedented high selectivity to total alcohols (53.7%) at a CO conversion of 34.0% under 200 °C and 24 h of reaction time . The reaction pathway is shown in Figure b.…”

“…(b) Production of higher alcohols from syngas via the integration of FTO and hydroformylation in a tandem process. Reprinted with permission from ref . Copyright 2022 Wiley-VCH Verlag GmbH & Co. KGaA.…”

“…Very recently, Jeske et al reported that tandem integration of a heterogeneous metallic Co-based NP (NaPr−CoRu/AOmM) FTO catalyst and a homogeneously Co-based molecular olefin hydroformylation catalyst (Co 2 CO 8 +PCy 3 ) in a batch reactor can achieve an unprecedented high selectivity to total alcohols (53.7%) at a CO conversion of 34.0% under 200 °C and 24 h of reaction time. 162 The reaction pathway is shown in Figure 16b. Obviously, such a relay coupling strategy provides a reliable solution to dismantle originally complex and uncontrollable coupling reactions on a single catalyst into multistep reactions in series.…”