Reaction of Methanol with TiC and VC (100) Surfaces

Abstract

The reaction of methanol on the (100) surfaces of single crystal vanadium carbide (VC) and titanium carbide (TiC) has been studied using high resolution electron energy loss spectroscopy (HREELS), temperature programmed desorption (TPD), and X-ray photoelectron spectroscopy (XPS). Methanol forms a mixed monolayer of molecular methanol and a methoxy intermediate upon adsorption at 153 K on both VC(100) and TiC(100). With increasing temperature, methanol is evolved from both surfaces through molecular and recombinative desorption. Approximately half of the methoxy intermediate reacts with the VC surface to produce formaldehyde and hydrogen, with a small amount of methane and persistent oxygen surface species. By contrast, very little of the methoxy intermediate reacts with the TiC surface, producing methane and hydrogen. A model of the surface reactions has been constructed based upon differences in the electronic structures of the carbide substrates.

Effect of interparticle interaction on the low temperature oxidation of CO over size-selected Au nanocatalysts supported on ultrathin TiC films

“…Samples containing gold nanoparticles with the same average height (and similar diameter) but different interparticle distances were synthesized by micelle encapsulation and deposited on ultrathin TiC films. Transition metal carbides such as TiC have great potential as catalytic supports in industrial applications [40] due to their high melting point, corrosion resistance [41], and proven reactivity with water, ethanol [42], methanol [43], and SO 2 [42]. Furthermore, for certain chemical reactions, transition metal carbides have shown catalytic activities that are similar to those reported for Pt, Pd, Rh, and Ru [44].…”

The stability of TiC surfaces in the environment with various carbon chemical potential and surface defects

“…The performance of TMCs in these technological applications is sensitive to the surface morphology and facet orientation of nanoparticles, [16][17][18][19][20][21] which mainly depends on the growth rate of the low-index surfaces. Surface energy, a fundamental property towards stability of clean solid surfaces, is known to influence the growth rate, catalytic behavior, surface segregation and the formation of grain boundaries, and it actually varies with the environment outside.…”

Comparative studies of methanol decomposition on carbide-modified V(110) and Ti(0001)

“…The fundamental understanding of the surface reaction of methanol on transition metal carbides is important for both tribological [1][2][3] and catalytic [4][5][6][7][8][9] applications. For example, adsorption studies of methanol on model surfaces can assist in understanding the interaction between carbide coatings and lubricant additives [3].…”

“…For example, adsorption studies of methanol on model surfaces can assist in understanding the interaction between carbide coatings and lubricant additives [3]. In addition, Groups 4-6 early transition metal carbides often show catalytic properties similar to those of the Pt-group metals [10][11][12][13][14][15][16][17][18].…”

“…Alternatively, Frantz et al have investigated the surface chemistry of methanol on bulk carbide single crystals such as TiC(1 0 0) and VC(1 0 0) [3]. These authors showed that partial decomposition (77%) of methanol to methoxy on TiC(1 0 0) occurred at liquid nitrogen temperature [3]. As the surface temperature was increased, the predominant reaction pathway was the recombinatory desorption of methanol.…”