Lidong Li

Technical University of Lisbon | UTL · Centre for Structural Chemistry (CQE)

A series of alumina-supported Ni catalysts were prepared to examine their activity and carbon deposition during dry reforming of methane (DRM). With an increase in the final calcination temperature to T=900 °C to form exclusively NiAl2O4, a catalyst with strong metal–support interactions was obtained. During a long-term DRM reaction (of about t=100...

Surface composition and structure are of vital importance for heterogeneous catalysts, especially for bimetallic catalysts, which often vary as a function of reaction conditions (known as surface segregation). The preparation of bimetallic catalysts with controlled metal surface composition and structure is very challenging. In this study, we synth...

A new dry reforming of methane catalyst comprised of NiCo bimetallic nanoparticles and a Mgx(Al)O support that exhibits high coke resistance and long-term on-stream stability is reported. The structural characterization by XRD, TEM, temperature-programmed reduction, and BET analysis demonstrates that the excellent performance of this catalyst is as...

An embodiment of the present disclosure provides method to prepapre supported Ni/Pt bimetallic nanoparticle having a Ni core and a Pt outter layer disposed on the surface of the Ni core, wherein Pt/Nis has a molar ratio of about 0.01 to 1 , and wherein the supported Ni/Pt bimetallic nanoparticle is deposited on a refractory porous support. In an em...

Preparing evenly-dispersed small size nickel nanoparticles over inert oxides remains a challenge today. In this context, a versatile method to prepare supported small size nickel nanoparticles (ca. 1-3 nm) with narrow size distribution via a surface organometallic chemistry (SOMC) route is described. The grafted mono(η(3)-allyl)nickel complexes [tr...

Preparing evenly-dispersed small size nickel nanoparticles over inert oxides remains a challenge today. In this context, a versatile method to prepare supported small size nickel nanoparticles (ca. 1-3 nm) with narrow size distribution via a surface organometallic chemistry (SOMC) route is described. The grafted mono(eta(3)-allyl) nickel complexes...

A series of new cationic and neutral (Ar-BIAN)copper(I) complexes [in which Ar-BIAN = bis(aryl)acenaphthenequinonediimine] was synthesised and characterised by elemental analysis, 1D and 2D NMR spectroscopy and single-crystal Xray diffraction. The cationic complexes of the general formula [Cu(Ar-BIAN)L2]BF4 [L2 = (PPh3)2 (1), dppe (2), dppf (3), (A...

A series of Ar-BIAN-based copper(I) complexes (where Ar-BIAN = bis(aryl)acenaphthenequinonediimine) were synthesised and characterised by (1)H and (13)C NMR spectroscopies, FT-IR spectroscopy, MALDI-TOF-MS spectrometry, cyclic voltammetry and single crystal X-ray diffraction. The bis-chelated complexes of general formula [Cu(Ar-BIAN)(2)]BF(4) (wher...

The key advances in oligo- or polymerization of olefins catalyzed by the 2,6-bis(imino)pyridine-based iron and cobalt complexes were presented. Particular attention was paid to trace the structural evolution of the 2,6-bis(imino)pyridine and related ligands, recent understandings of the relationship between catalyst structure and catalytic activity...

A series of zinc complexes of the general formula {[ZnCl(ArN=C(An)-C(An)=NAr)](+)}(2)[Zn(2)Cl(6)](2-) (where Ar = 2-(1-benzyl-1H-1,2,3-triazol-4-yl)phenyl 2a, 2-(1-(1-phenylethyl)-1H-1,2,3-triazol-4-yl)phenyl 2b, 2-(1-phenyl-1H-1,2,3-triazol-4-yl)phenyl 2c; An = acenaphthene backbone) were prepared by the condensation of acenaphthenequinone with th...

A series of three recently synthesised tetradentate chelated alpha-diimine nickel complexes of the type [NiBr2(Ar-BIAN)] (where Ar = 2-(1-R-1H-1,2,3-triazol-4-yl)phenyl; R = benzyl 1, 1-phenyl-ethyl 2, phenyl 3) are used as precatalysts for the polymerisation of norbornene. When activated with MAO, 1-3 are highly active catalysts for the production...

The reaction of two commercially available compounds, phenanthrenequinone and 2,6dialkylaniline (alkyl = Me, iPr), catalyzed by formic acid, in refluxing methanol, gave rise exclusively to 10-(2,6-dialkyl-phenylimino)-10H-phenanthren-9-one compounds (alkyl = Me (1), iPr (2)). In refluxing toluene, and when diisopropylaniline is employed, the hetero...

Two 9,10-phenanthrenequinone-based α-diimine ligands (N,N′Z, N,N′E)-N,N′-(phenanthrene-9,10-diylidene)bis(2,6-dimethylaniline) (1) and (Z)-2,6-dimethyl-N-((E)-10-methylbenzo[f]phenanthro[10,1-bc]azepin-8(14H)-ylidene)aniline (2), were prepared by condensation of 2,6-dimethylaniline and 9,10-phenanthrenequinone in the presence of the TiCl4/1,4-diaza...

The reaction of two commercially available compounds, phenanthrenequinone and 2,6-dialkylaniline (alkyl = Me, iPr), catalyzed by formic acid, in refluxing methanol, gave rise exclusively to 10-(2,6-dialkyl-phenylimino)-10H-phenanthren-9-one compounds (alkyl = Me (1), iPr (2)). In refluxing toluene, and when diisopropylaniline is employed, the heter...

Two conformational polymorphs of trans-chlorido(phenyl)bis(triphenylphosphine)nickel(II), [Ni(C(6)H(5))Cl(C(18)H(15)P)(2)], (1), viz. orange needle-shaped crystals (form I) and brown prism-shaped crystals (form II), were obtained under different crystallization conditions from a mixture of toluene and n-hexane, and characterized by single-crystal X...

Synthesis and Characterization of 8-(2-((Trimethylsilyl)ethynyl)phenylamino)-7H-naphtho[1,8-bc]acridin-7-one(2008)'Synthesis and Characterization of 8-(2-((Trimethylsilyl)ethynyl)phenylamino)-7H-naphtho[1,8-bc]acridin-7-one',Synthetic Communications,38:24,4415 — 4425

Five different tetraalkylaluminoxanes, tetraisobutylaluminoxane (A1), ethyltriisobutylaluminoxane (A2), diethyldiisobutylaluminoxane (A3), triethylisobutylaluminoxane (A4) and tetraethylaluminoxane (A5), were prepared to polymerize ethylene in the presence of iron complexes [((2,6-RPh)NC(Me))2C5H3N]FeCl2 (RMe, M1; Riso-Pr, M2). Except M1/A1 and M2/...

In the presence of tetraethylaluminoxane (TEAO), iron complexes were used to catalyze ethylene polymerizations with extremely high activities and generally produced polyethylene with a bimodal molecular weight distribution (MWD). This bimodal MWD of polyethylene was mainly derived from residual triethylaluminum in TEAO and was produced through a me...

Through immobilization of two iron-based complexes, [((2,6-MePh)N = C(Me))2C5H3N]FeCl2 (1) and [((2,6-iPrPh)N = C(Me))2C5H3N]FeCl2 (2), on SiO2 pretreated with tetraethylaluminoxane (TEAO), two supported iron-based catalysts, 1/TEAO/SiO2 (3) and 2/TEAO/SiO2 (4), were prepared. These two supported catalysts 3 and 4 could be used to catalyze ethylene...

An analysis of 17O carbonyl chemical shifts of 50 substituted benzaldehydes leads to an empirical equation, delta(cal)(17O) = 564.0 + (sigma)(delta)o + (sigma)(delta)m + (sigma)(delta)p + C, for calculating 17O chemical shifts. This equation is based on a linear regression analysis using 11 substituent parameters and leads to good conformity with t...

A series of aluminoxanes, tetraethylaluminoxane (TEAO), tetraalkylaluminoxane (TAAO), Et2AlOB(4 − F − C6H4)OAlEt2 (BTEAO) and ethyl‐iso‐butylaluminoxane modified with p‐fluorophenylboric acid (BEBAO), were prepared and their effects on molecular weight (MW) and molecular weight distribution (MWD) of polyethylene prepared by the iron‐based catalyst...

Polyethylenes with bimodal molecular weight distribution (MWD) were synthesized by 2,6-bis(imino)pyridyl complexes of Fe(II) combined with different activators, which were prepared from alkylaluminium. It is found that the molecular weight (MW) and MWD was influenced by not only iron complexes but activators as well. The activator plays key importa...