State Key Laboratory of Green Chemical Engineering and Industrial Catalysis, Shanghai Research Institute of Petrochemical Technology, SINOPEC Corp., Shanghai, 201208, China.
China Petrochemical Corporation (SINOPEC Group), Beijing, 100728, China.
Nat Commun. 2019 Mar 21;10(1):1297. doi: 10.1038/s41467-019-09336-1.
Direct synthesis of light olefins from syngas (STO) using a bifunctional catalyst composed of oxide and zeolite has attracted extensive attention in both academia and industry. It is highly desirable to develop robust catalysts that could enhance the CO conversion while simultaneously maintain high selectivity to C2-C4 olefins. Herein, we report a bifunctional catalyst consisting of ZnCr binary oxide (ZnCrO) and low-Si AlPO-18 zeolite, showing both satisfying selectivity to C2-C4 olefins of 45.0% (86.7%, CO free) and high olefin/paraffin ratio of 29.9 at the CO conversion of 25.2% under mild reaction conditions (4.0 MPa, 390 °C). By optimizing the reaction conditions, the CO conversion could be markedly increased to 49.3% with a slight drop in selectivity. CDCN/CO-FTIR characterizations and theoretical calculations demonstrate that low-Si AlPO-18 zeolite has lower acid strength, and is therefore less reactive toward the hydride transfer in the STO reaction, leading to a higher olefin/paraffin ratio.
使用由氧化物和沸石组成的双功能催化剂将合成气（STO）直接转化为低碳烯烃在学术界和工业界都引起了广泛关注。开发能够提高 CO 转化率同时保持对 C2-C4 烯烃高选择性的稳健催化剂是非常可取的。在此，我们报告了一种由 ZnCr 二元氧化物（ZnCrO）和低-Si AlPO-18 沸石组成的双功能催化剂，在温和的反应条件（4.0 MPa，390°C）下，当 CO 转化率为 25.2%时，具有令人满意的 C2-C4 烯烃选择性（45.0%（86.7%，无 CO）和高烯烃/石蜡比（29.9）。通过优化反应条件，CO 转化率可显著提高至 49.3%，而选择性略有下降。CDCN/CO-FTIR 表征和理论计算表明，低-Si AlPO-18 沸石具有较低的酸强度，因此在 STO 反应中的氢转移反应性较低，导致较高的烯烃/石蜡比。
