▎ 摘　　要

NOVELTY - A catalyst comprises a carbon material (a) comprising a nitrogen-doped carbon material comprising a graphene structure in which nitrogen atoms are substituted or introduced, and having a molar ratio of nitrogen atom with respect to carbon atom of 0.003-0.300 measured by X-ray photoelectron spectroscopy, an organoaluminum compound (b), and a transition metal compound (c). USE - Catalyst is used for manufacturing olefin polymer (claimed) e.g. ethylene polymer. ADVANTAGE - The catalyst has high polymerization activity, and can be manufactured by economical method without using expensive organic aluminum oxy compound. The carbon material is efficiently dispersed in the catalyst. The carbon material has improved thermal conductivity, electroconductivity and weather resistance. DETAILED DESCRIPTION - A catalyst comprises a carbon material (a) comprising a nitrogen-doped carbon material comprising a graphene structure in which nitrogen atoms are substituted or introduced, and having a molar ratio of nitrogen atom with respect to carbon atom of 0.003-0.300 measured by X-ray photoelectron spectroscopy, an organoaluminum compound of formula: R'amAl(OR'b)nHpXq (b), and a transition metal compound of formula: Lm'MXn' (c). R'a,R'b = 1-15C hydrocarbyl; X = halo; m = 1-3; n,p,q = 0-2; m+n+p+q = 3; M = group 3 atom, group 4 atom, group 5 atom, group 6 atom, group 7 atom, group 8 atom, group 9 atom, group 10 atom, group 11 atom and lanthanide atom in periodic table; L = ligand comprising atom(s) chosen from boron, nitrogen, oxygen, phosphorus, sulfur and selenium; m' = 2 or more; n' = 1-4;and X = leaving group, preferably H, halo, hydrocarbyl, halo-containing group, silicon-containing group, oxygen-containing group, sulfur-containing group, nitrogen-containing group, phosphorus-containing group, boron-containing group, aluminum-containing group, conjugated diene-based derivative group or neutral ligand capable of coordinating with isolated electron pair. An INDEPENDENT CLAIM is included for manufacture of olefin polymer, which involves (i) polymerizing an olefin in the presence of the catalyst. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a structure of a liquid plasma generator used for manufacturing the carbon material. Liquid phase (2) Plasma phase (4) Container (5) Electrode (6) External power supply (8)