Examination of Milstein Ru-PNN and Rh-Tribi/Tetrabi dual metal catalyst for isomerization-linear-hydroformylation of C4 raffinate and internal olefins

Isomerization-linear-hydroformylation is demanding, however, not an addressed issue, for the production of value-added linear aldehydes by converting cheap and abundant internal alkenes available from bio- & petrochemical industry. In this paper, a dual metal catalysis system combining a Ru-isomerization catalyst and a Rhlinear-hydroformylation catalyst satisfying the 4S criterions was reported for isomerization-linearhydroformylation of C4 raffinate (mixed butenes) and internal olefins. The optimized dual metal catalyst system hydroformylated Raffinate II feed to valuable valeraldehyde in 98% linear selectivity (n:i = 49), 80% conversion and high activity of 1069 h-1 TOF whereas 96% linear selectivity (n:i = 24), 71% conversion and 948 h-1 TOF were observed using only the Rh-hydroformylation catalyst. Notably, valeraldehyde are produced in million tons scale annually for making non-toxic plasticizer DPHP. Various 2-olefins were also converted to linear aldehydes in > 98% linear selectivity (n:i > 49), 78%-82% conversion and high activity of 802-851 h-1 TOF.

Automated summary

This paper reports a dual metal catalysis system combining a Ru-isomerization catalyst and a Rh-linear-hydroformylation catalyst for the production of value-added linear aldehydes from C4 raffinate and internal olefins. The optimized dual metal catalyst system showed high selectivity and conversion for the synthesis of linear aldehydes.