Über katalytische Wirkungen kolloidaler Metalle der Platingruppe. XII. Die stufenweise Reduktion des Acetylens

Abstract

sternformig vereinigten Nadelo oder Prismen scheidet er sich aus der IA~ung in Chloroforni nach Zusatz von Petroliitber ab. I n kaltem Eisessig, Aceton, Chloroform und Essigiither ist er leicht liislicb, in Ather erheblich schwerer.SchlieBlich sage ich 1Irn. Dr. 3Iax B e r g n i a n t i fiir seine aertvolle Hilfe herzlicheu Dank. C. Paal und OhrietianHohenegger: fher katalgtische Wirkungen kolloidaler Metalle der Platingrmppe. XII. Die atufenwelse Reduktion des Acetylens. [iUittc.ilung nns deni Pliarm.-chcm. Institut dcr Cnivcrsitiit Erlangen.] (Eingcg:iogen am G. Fcbriiar 1915.) \'or Iangerer Zeit batte der kine von uns i n Gerueinscliaft rtiit W. H a r t m a n n iiber die k a t n l y t i s c h e H y d r o g e n i s a t i o n d e r P h e n y 1p r o pi o 1 s a u r e I), C6IIs.C C.COOII, mit k o 11 o i d a l e ni P a 11 adium') und Wasserstoff berichtet, die so stufenweise die m n l e i n o i d e P o r m d e r Z i m t s i u r e , und zwar primgr die labilste der 3 Uodi-fikationen3), utid bei weiterer Ketluktion die 1 I y d r o x i r n t s i i u r e lieferte. Kbenso war schon fruher von deni eineri ron tins lint1 G e r u i o gezeigt worden, dali :tuch die Z i m t s i i u r e Lei tier katalytischen Hydrogenisation mit kolloidnlem Palladium oder l'latin in IIytlrozimtsiiure iibergeht ').

Selective ensembles in supported palladium sulfide nanoparticles for alkyne semi-hydrogenation

“…Examination of the rich scientific literature emphasizes the wide dominance of palladium-based catalysts, due to the ability to dissociate hydrogen, and the importance of preventing the undesired hydrogenation of competing functional groups through electronic poisoning with suitable modifiers (Fig. 1 ) 6 – 35 . Similarly, oligomerization paths (C–C couplings) must be suppressed by the strict control over the ensemble size.…”

“…1 Survey of alkyne semi-hydrogenation catalysts. Chronological development for gas- and liquid-phase applications tracing from the pioneering works of Wilde 1 and Sabatier 2 to the more recent discoveries 6 – 35 . Six prominent catalyst families can be distinguished based on (i) supported metal nanoparticles, (ii) intermetallics, alloys, and Lindlar-type formulations where Pd is poisoned by a second metal, (iii) ligand-modified or hybrid materials featuring an organic surfactant that partially covers the surface of Pd nanoparticles, (iv) metal oxides, (v) supported single atoms, and (vi) Pd modified by p -block elements.…”

“…However, the recent disruptive legislations restricting the use of hazardous compounds have steered the innovation and creativity of scientists towards the development of sustainable alternatives. This has enabled the incorporation of new families of hydrogenation catalysts based on: (i) alternative metals 1 , 2 , 7 , 9 , 10 , 30 , (ii) alloy and intermetallic compounds 8 , 11 – 16 , 18 – 21 , (iii) ligand-modified nanoparticles 6 , 17 , 22 , 25 , (iv) transition metal oxides 26 , 27 , 34 , 35 , and (v) supported single atoms 24 , 31 , 32 . While these share better ensemble definition than unmodified Pd, intrinsic drawbacks like instability against high pressure induced segregation for intermetallics 44 – 46 , accessibility constraints in ligand-modified and single atom catalysts 31 , 47 , and poor H 2 activation on oxides 48 have been identified.…”