An Efficient and Practical System for the Synthesis of N,N-Dimethylformamide by CO2 Hydrogenation using a Heterogeneous Ru Catalyst: From Batch to Continuous Flow

Abstract

In the context of CO₂ utilization, a number of CO₂ conversion methods have been identified in laboratory-scale research; however, only a very few transformations have been successfully scaled up and implemented industrially. The main bottleneck in realizing industrial application of these CO₂ conversions is the lack of industrially viable catalytic systems and the need for practically implementable process developments. In this study, a simple, highly efficient and recyclable ruthenium-grafted bisphosphine-based porous organic polymer (Ru@PP-POP) catalyst has been developed for the hydrogenation of CO₂ to N,N-dimethylformamide, which affords a highest ever turnover number of 160 000 and an initial turnover frequency of 29 000 h^-1 in a batch process. The catalyst is successfully applied in a trickle-bed reactor and utilized in an industrially feasible continuous-flow process with an excellent durability and productivity of 915 mmol h^-1 g_Ru ^-1 .

Keywords: carbon dioxide; heterogeneous catalysis; hydrogenation; porous organic polymers; ruthenium.