from first principles PP-I-1

PP-IV-6Application of the Concept of Interlayer Dynamics for Designof Novel TMS-Based Catalysts for Synthesis of Mixed AlchoholsDorokhov V.S. 1 , Ishutenko D.I. I,2 , Nikulshin P.A. 2 , Eliseev O.L. 1 , Bondarenko T.N. 1 ,Lapidus A.L. 1 , Kogan V.M. 11 N.D. Zelinsky Institute of Organic Chemistry, Moscow, Russia2 Samara State Technical University, Samara, Russiavitekd88@yandex.ruIn recent time much attention was attracted to alternative fuels such as alcohols. Conventionaloxide catalysts used for alcohols synthesis are very sensitive to the presence of ultra-lowsulphur amount in the feed sulphur. One of the ways to overcome this difficulty is to usesystems based on widely used for hydrodesulphurization (HDS) transition metal sulphide(TMS) catalysts, modified for alcohol synthesis by addition of potassium. The aim of thepresent work is to investigate a structure of sulphide catalyst active sites in mixed alcoholsynthesis (MAS). As a conceptual basis for this work the model of dynamic nature of theactive sites of TMS catalysts was taken [1].The results of investigation into the effect of carrier structure allowed us to assume thatmorphological characteristics and nature of the carriers essentially affect the catalytic activity.Information about a role of K in the catalytic activity was obtained by testing the sampleswith K content in the range 0-15 wt. %. With increasing of K content selectivity changes fromHC to alcohols. Main part of the liquid products consists of С 1 -С 4 alcohols (>85 wt. %),ethanol and propanol has concentrations more than methanol. Potassium concentration affectssubstantially HDS and HYD activities. In these reactions K represents itself a poison andprimary poisons HYD active sites. Addition of K up to 10 wt. % reduces catalysts HDSactivity in small extent, but reduces HYD activity. Poisoning of C-S hydrogenolysis sitesoccurs by increasing K concentration to 15 wt. %,. Basing on TEM data we suggested that Kions intercalates between two neighboring MoS 2 layers. Above 10 wt. % K “glues” MoS 2slabs by basal planes growing layers number. Further increase of K content from 10 to 15 wt.% initiates growth of an average crystallite length via "sticking" by laterals.Potassium affects active phase morphology and modifies the active sites of the TMS catalysts.It was shown that Co-promoted catalyst more selective to alcohols than unpromoted one. Theobserved Co promoting activity in MAS and HDS led us to conclusion about similarity in thenature of the active sites operating in both reactions.References1. V.M. Kogan, P.A. Nikulshin, Cat. Today 149 (2010) 224.290