Current approaches for efficient C À H bond activation are usually mediated by heterogeneous [1] or homogeneous [2] catalysts. The basis is the employment of transition metals or organometallic centers, which is pivotal for the successful attack on the targeted C À H bonds. [3] However, we have reported that it is feasible to use carbon-based nanomaterials to activate short-chain alkanes in catalytic dehydrogenation reactions [4] although relatively high reaction temperatures are required. It is of particular interest to know whether it is possible to activate CÀH bonds to get high value-added products at a moderate reaction temperatures by using cheap metal-free catalysts. To this end, an elegant approach using metal-or boron-doped carbon nitrides as catalysts [5] has been developed for the selective oxidation of allylic and benzylic hydrocarbons in organic solvents with moderate conversion. Attempts to achieve higher activity also include the application of N-alkoxysulfonyloxaziridines for the activation of C(sp 3 ) À H bonds, [6] although a complicated catalytic system for efficient reaction circulation was required.Layered carbon, that is, highly exfoliated graphitic structures containing one or a few graphene layers, [7] has an unconventional electronic structure, [8] which was speculated to have a high chemical reactivity. [9] Indeed, researchers observed that layered carbon can catalyze hydrogenation, [10] ring-opening polymerization, [11] and CÀH oxidation reaction, [12] and that it could serve as a support for metal oxide catalysts. [13] Herein we describe nitrogen-doped graphene materials that can activate the benzylic C À H bond with exceptionally high activity. The nitrogen atoms introduced are preferentially bound at graphitic sites in the carbon framework. This induces high charge and spin density at the adjacent ortho carbon, which promotes the formation of reactive oxygen species and the materials display exceptional catalytic activity even at room temperature.Firstly, we examined the oxidation of ethylbenzene in aqueous phase with tert-butyl hydroperoxide (TBHP) as the oxidant and without using catalyst. However, no obvious activity was observed by GC after a reaction time of 24 h (Table 1, entry 1). Then we used a graphene sample prepared by the arc-discharge method (referred to as Arc-C) [14] as the catalyst for this reaction. Surprisingly, Arc-C activated ethylbenzene at 353 K to generate acetophenone in 20.7 % yield (Table 1, entry 2). As Arc-C had been prepared by a directcurrent arc-discharge method with a pure graphite rod as the electrode in an NH 3 /He atmosphere, besides trace nitrogen (0.7 %), no element other than carbon was detected by elemental analysis (EA) (oxygen cannot be detected by this method). The full X-ray photoelectron spectrum showed a C content of 97.9 % and low amounts of nitrogen and oxygen of 0.9 % and 1.1 %, respectively. This promising observation suggests that it is layered carbon material itself that catalyzed the oxyfunctionalization of the hydrocarbon. As Arc-C...

External" nitrogen doped graphene sheets via pyridyne cycloaddition were fabricated, which can serve as feasible Pt alternatives for oxygen reduction reaction electrocatalysts. Notably, the excellent ORR performance of PyNGs can be attributed to the possible adsorption and catalytic site of the ortho-carbon of "external" nitrogen.

Aktiv dank Stickstoff: Der Einbau von graphitischem Stickstoff in Mehrlagengraphen erhöht die chemische Reaktivität der Kohlenstoffatome. Dadurch können reaktive Sauerstoffspezies einfach gebildet werden, was diesem Katalysator sogar bei Raumtemperatur eine hohe Aktivität in der Aktivierung von Kohlenwasserstoffen verleiht.

A resorcinol-formaldehyde resin carbon (RFC) catalyst with a well-developed, ordered, mesoporous framework was prepared using a soft template method at room temperature. The carbon was sulfonated in water using sulfanilic acid under mild atmospheric conditions. The sulfonated RFC (S-RFC) was characterized by N 2 adsorption-desorption, elemental analysis, TEM, XPS, and FT-IR. It was determined that S-RFC is an efficient solid acid catalyst for furfural production from xylose and corn stover in gvalerolactone (GVL). The effects of reaction time, reaction temperature, catalyst loading, substrate dosage and water concentration were investigated. 80% furfural yield and 100% xylose conversion were obtained from xylose at 170 C in 15 min with 0.5 g catalyst. Comparatively, 68.6% furfural yield was achieved from corn stover at 200 C in 100 min when using 0.6 g catalyst. Since there was no discernable decrease in furfural yield after multiple conversions utilizing the same catalyst, the recyclability of the catalyst is considered good.