Solid Molecular Phosphine Catalysts for Formic Acid Decomposition in the Biorefinery

Abstract

The co-production of formic acid during the conversion of cellulose to levulinic acid offers the possibility for on-site hydrogen production and reductive transformations. Phosphorus-based porous polymers loaded with Ru complexes exhibit high activity and selectivity in the base-free decomposition of formic acid to CO2 and H2 . A polymeric analogue of 1,2-bis(diphenylphosphino)ethane (DPPE) gave the best results in terms of performance and stability. Recycling tests revealed low levels of leaching and only a gradual decrease in the activity over seven runs. An applicability study revealed that these catalysts even facilitate selective removal of formic acid from crude product mixtures arising from the synthesis of levulinic acid.

Hydrogenation of CO2 to Formate over Ruthenium Immobilized on Solid Molecular Phosphines

“…A series of catalysts based on P‐ and N‐donor‐containing polymers loaded with Ru and Ir was screened to assess the activity of the polymers in the aqueous hydrogenation of CO 2 to FA − . Catalysts were prepared by stirring the polymeric supports (pTPP, pDPPE, pTPPB, pTPrP, bpy‐CTF, CTF‐b; Figure ) with either [{Ru( p ‐cymene)Cl 2 } 2 ] or [{IrCp*Cl 2 } 2 ] in methanol, followed by filtration . Inductively coupled plasma optical emission spectroscopy (ICP‐OES) of the filtrate confirmed complete (>99 %) uptake in all cases.…”

“…The polymers pTPP and pDPPE (Figure ) were prepared as described previously . To study the effect of linker topology on the porosity and electronic structure, two additional polymers were synthesized.…”

“…This shows that the direct immobilization of molecular complexes onto functionalized porous polymers leads to improved catalytic activity and is a promising strategy for catalyst design . The polymeric analogs of triphenylphosphine (pTPP) and 1,2‐bis(diphenylphosphino)ethane (pDPPE), already showed high activity in the decomposition of aqueous base‐free FA . So far, phosphine‐based polymers have not been reported for the hydrogenation of CO 2 to FA − .…”

Production of γ‐Valerolactone from One‐Pot Transformation of Biomass‐Derived Carbohydrates Over Chitosan‐Supported Ruthenium Catalyst Combined with Zeolite ZSM‐5

“…[34] Previous studies indicated that PPh 3 can act as an electron-donor additive [35] and have a weak interaction with Ru 3+ ions, which can facilitate the decomposition of FA, thus being beneficial for the hydrogenation. [36] Therefore, the presence of PPh 3 is also crucially important for the reaction. Without PPh 3 , only 30 % yield of GVL could be produced from one-pot conversion of FF.…”

Biogenic Formic Acid as a Green Hydrogen Carrier

“…No Ru leaching was detected after at urnover numbero f7 1000, which correspondst o2 0f ull cycles of full conversion. Palkovits et al [74] used porous phosphorous-based phenyl-polymers as the support in asimilar catalytic system. Their heterogeneous catalyst had an even higher activity for the dehydrogenation of aqueous dilute FA solutions.…”