Revisiting formic acid decomposition on metallic powder catalysts: Exploding the HCOOH decomposition volcano curve

Abstract

This study revisits the classic volcano curve for HCOOH decomposition by metal catalysts by taking a modern catalysis approach. The metal catalysts (Au, Ag, Cu, Pt, Pd, Ni, Rh, Co and Fe) were prepared by H 2 reduction of the corresponding metal oxides. The number of surface active sites (Ns) was determined by formic acid chemisorption. In situ IR indicated that both monodentate and bidentate/bridged surface HCOO* were present on the metals. Heats of adsorption (ΔH ads) for surface HCOO* values on metals were taken from recently reported DFT calculations. Kinetics for surface HCOO* decomposition (k rds) were determined with TPD spectroscopy. Steady-state specific activity (TOF = activity/Ns) for HCOOH decomposition over the metals was calculated from steady-state activity (µmol/g-s) and Ns (µmol/g). Steady-state TOFs for HCOOH decomposition weakly correlated with surface HCOO* decomposition kinetics (k rds) and ΔH ads of surface HCOO* intermediates. The plot of TOF vs. ΔH ads for HCOOH decomposition on metal catalysts does not reproduce the classic volcano curve, but shows that TOF depends on both ΔH ads and decomposition kinetics (k rds) of surface HCOO* intermediates. This is the first time that the classic catalysis study of HCOOH decomposition on metallic powder catalysts has been repeated since its original publication.

Adsorption and Decomposition of Formic Acid on Cobalt(0001)

“…The observation of formate at this temperature is consistent with this reaction on other cobalt surfaces and other transition metals 33,69 and with the low barrier in the reaction scheme. Formation of the carboxyl species should be expected at the same time as the formate, since the two paths have similar barriers, however the carboxyl species was not observed experimentally either because its C 1s signature could not be resolved (Table S1 lists the calculated peak positions for the C 1s photoelectron for all the fragments) or because it decomposes shortly after being produced via CO formation.…”

Catalytic Transfer Hydrogenation of Furfural to Furfuryl Alcohol by using Ultrasmall Rh Nanoparticles Embedded on Diamine‐Functionalized KIT‐6

“…The ultrafine Rh particles in Rh/ED‐KIT‐6 must be active for the hydrogenation of FFR but not as active for FA decomposition to maintain the slow but steady release of active H species in the presence of FA as the hydrogen donor; too high decomposition and low activity for hydrogenation would generate a large quantity of H 2 gas, not the hydrogenation product. In fact, Pd is known as the most active catalyst for FA decomposition to H 2 gas, but as shown in Table , its CHT reaction rate was far below that of Rh/ED‐KIT‐6.…”

Pd Catalysts Supported on Bamboo-Like Nitrogen-Doped Carbon Nanotubes for Hydrogen Production

“…Hydrogen production from formic acid (FA) is a way to involve renewable biomass sources into the energy cycle [1,2]. The FA decomposition reaction proceeds on mono-, bi-and trimetallic catalysts deposited on oxide or carbon supports [3,4]. Activity and selectivity of the catalysts towards hydrogen production are determined by the nature of their active component, its dispersion, and electronic state of metals.…”

“…Additionally, for platinum deposited on nitrogen-doped carbon nanofibers (N-CNFs) and N-CNTs, it 2 of 13 was shown that the catalytic properties of metal in this reaction are determined by its locally one-type interaction with N Py centers [16]. Among various metals that are active towards FA decomposition, platinum and palladium are the most active catalysts for this reaction [3,17]. It should be noted that the use of N-CNMs as the supports opens new possibilities for enhancing the efficiency of catalysts via the stabilization of highly active and selective atomic metal species [18,19].…”