In situ FTIR study of low-pressure hydroformylation of 1-hexene catalyzed by ultrafine cobalt nanoparticles

The hydroformylation of 1-hexene in syngas (CO:H2 = 1) under 2–3 MPa at 100 °C was catalyzed using 2.8 nm ultrafine cobalt nanoparticles and investigated by in situ Fourier transform infrared spectroscopy (FTIR). A group of bands observed in the in situ FTIR spectra at 2071, 2041, and 2022 cm−1 are assigned to terminal CO adsorptions distributed over different Co sites. A band at 2054 cm−1 is attributed to the intermediate, RCH2CH2COCo, which has been observed for the first time. Through this intermediate, the catalytic reaction proceeds via the elimination of RCH2CH2COCo to leave a single H atom on the surface of each 2.8-nm Co nanoparticle.

摘要利用原位透射红外光谱研究了2.8 nm超细钴纳米粒子在2 ∼ 3 MPa合成气(CO:H2 = 1:1)和100 °C条件下催化的1-己烯氢甲酰化反应. 结果表明, 在反应中出现与Co2(CO)8类似的红外吸收峰(2071, 2041和2022 cm−1), 被证明是不同Co位点端式吸附CO. 首次观测到了位于2054 cm−1处吸收峰处的物种, 可能归属为RCH2CH2COCo. 通过此中间物种，产物醛可以在钴催化剂表面经由结合一个氢原子脱除反应而获得.

An in situ FTIR observation of the hydroformylation reaction conducted using a Co nanoparticle-based system suggests that some of the observed bands in the FTIR spectrum are similar to those of the original Co complex. The unique absorption band at 2054 cm−1 corresponds to terminal CO adsorptions bound to different cobalt sites.Figure optionsDownload as PowerPoint slide