Lignin First: Confirming the Role of the Metal Catalyst in Reductive Fractionation

Rhodium nanoparticles embedded on the interior of hollow porous carbon nanospheres, able to sieve monomers from polymers, were used to confirm the precise role of metal catalysts in the reductive catalytic fractionation of lignin. The study provides clear evidence that the primary function of the metal catalyst is to hydrogenate monomeric lignin fragments into more stable forms following a solvent-based fractionation and fragmentation of lignin

Anchoring single platinum atoms onto nickel nanoparticles affords highly selective catalysts for lignin conversion

Due to the highly complex polyphenolic structure of lignin, depolymerization without a prior chemical treatment is challenging, and new catalysts are required. Atomically dispersed catalysts are able to maximize the atomic efficiency of noble metals, simultaneously providing an alternative strategy to tune the activity and selectivity by alloying with other abundant metal supports. Here, we report a highly active and selective catalyst comprising monodispersed (single) Pt atoms on Ni nanoparticles supported on carbon (denoted as Pt1Ni/C, where Pt1 represents single Pt atoms), designed for the reductive depolymerization of lignin. Selectivity toward 4-n-propylsyringol and 4-n-propylguaiacol exceeds 90%. The activity and selectivity of the Pt1Ni/C catalyst in the reductive depolymerization of lignin may be attributed to synergistic effects between the Ni nanoparticles and the single Pt atoms

Characterization of organometallic compounds in water

A review with 59 refs. concerning characterization of compds. contg. metal-carbon bonds in aq. solns. and pressurization of organometallic systems in water

Characterization of organometallic compounds in water

A review discussing the pressurization of organometallic systems in H2O. It deals with the effect of the high hydrostatic pressure on organometallics and the characterization of reactions involving pressurized gases with aq. organometallics

Synthesis and characterization of new water-soluble hydrides of Ru-II: A step towards dinitrogen activation?

The basic aqueous coordination chemistry of Ru-II has been studied using the catalytically important TPPTS phosphine (TPPTS = trisodium salt of 3,3 ',3 ''-phosphinetriylbenzenesulfonic acid) and small gas molecules (H-2, CO, N-2) as ligands. As a result, new water-soluble ruthenium mixed hydride complexes, presumably key species in many industrial catalytic processes, have been formed and identified. The Ru-II mixed hydrides were synthesized, and their formation was followed in situ by multinuclear NMR spectroscopy, pressurizing aqueous Ru-II-TPPTS systems with H-2 and CO gas in sapphire NMR tubes. The formation equilibrium of these complexes is highly dependant on the temperature and the gas pressures. Under 50 atm of N-2, the unique [RuH(CO)(N-2)(TPPTS)(2)(H2O)](+) complex has been identified, which could be the first step toward dinitrogen activation

Carbon dioxide reduction in biphasic aqueous-ionic liquid systems by pressurized hydrogen

This work reports the hydrogenation of carbon dioxide/inorganic carbonate salts to formic acid/formate in two phase systems comprising an ionic phase, in which the catalyst is immobilized, and an aqueous phase in which the carbonates and formate are confined, is reported. The reactions were followed in situ by multinuclear NMR. Pressurized H-2 gas was used for the reduction