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 Rh-linear-hydroformylation catalyst satisfying the“4S”criterions was reported for isomerization-linear-hydroformylation 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.