Polyketone (PK) has attracted wide attention owing to its direct utilization of carbon monoxide, excellent properties, and photodegradation performance. However, the commercialized PK is produced using Pd‐based catalysts, which accounts for the largest part of the production cost. Herein, [Ni(2‐tol)(PPh3)(N,O)] is used as the main catalyst for its high productivity and good tolerance to CO. Effects of the cocatalyst (Ni(COD)2), the aging method in CO atmosphere, and the polarity of solvent are investigated. When Ni(COD)2 is employed as the cocatalyst, the catalytic activity and molecular weight of PK are increased by 29% and 42.6%, respectively. Aging of catalyst system with Ni(COD)2 in CO atmosphere leads to significant decrease in activity and molecular weight, while aging has almost no effect on the copolymerization without Ni(COD)2. Different catalytic mechanisms are proposed for the catalyst system with and without cocatalyst. Furthermore, it is found that the polar solvent (CH2Cl2) significantly increases the activity by 119.2% compared to that in the nonpolar solvent (toluene). However, the thermal stability of the catalyst is much better in toluene. The study on the understanding of catalytic mechanism and improvement of activity will promote the practical application of nonprecious metal catalysts for preparation of PK.

Polyketone (PK) is a promising material because of its superior qualities as an engineering plastic and the direct use of CO. It is typically produced using slurry polymerization techniques, which cause reactor fouling and low bulk density product. Here, solution polymerization of CO/ethene/propene with high-molecular-weight products (240.3 kDa) and high catalytic activity (36.1 kg PK•g −1 Pd•h −1 ) was achieved utilizing a mixture of hexafluoroisopropanol (HFIP) and methanol. Both the activity and M w are an order of magnitude higher than those reported in the literature. HFIP was able to activate the palladium-based precatalyst without using any strong acid. The 31 P NMR, singlecrystal X-ray diffraction, and density functional theory analysis prove that HFIP decreased the coordination between palladium and the acetate ligands of the precatalyst without the disassociation of the acetate. Furthermore, the active centers in the HFIP system were more stable than that in the catalytic system with strong acid.