Tungsten Single-Atom Catalysts for the Efficient Conversion of Isobutene into Highly Branched Liquid Hydrocarbons

Abstract

The catalytic transformation of isobutene into branched liquid hydrocarbons is crucial for the production of reformulated gasoline and fuel additives. Conventional supported catalysts often lack high activity and selectivity toward the desired highly branched dimers and trimers in isobutene oligomerization. Here, by developing a tungsten single-atom catalyst (WSAC) atomically dispersed on a silica-doped alumina (SDA) support, we report that the WSAC/SDA catalyst enables efficient and selective conversion of isobutene into highly branched C₈ and C₁₂ liquid olefins, while suppressing the formation of heavier hydrocarbons. The atomically dispersed W₁–O₃ moieties incorporated within the SDA support were synthesized via a high-temperature pyrolysis of a templating zinc metal-organic framework (Zn-MOF) under argon, followed by annealing in static air. The WSAC/SDA catalysts with 1.6–3.7 wt.% W loading exhibited single-atom dispersion (~0.2 nm) and outstanding performance, achieving up to 60% and 95% selectivity to branched C₈ olefins at 150 °C and 250 °C, respectively, under ambient pressure. With the demonstrated high activity, selectivity, and stability, the WSAC/SDA catalyst system presents a promising platform for next-generation heterogeneous catalysts for the efficient and selective upgrading of isobutene into high-performance fuel additives.