Doping catalytic activity

The catalytic activity of doped nickel oxide on the solid state decomposition of CsN3 decreased [714] in the sequence NiO(l% Li) > NiO > NiO(l% Cr) > uncatalyzed reaction. While these results are in qualitative accordance with the assumption that the additive provided electron traps, further observations, showing that ZnO (an rc-type semi-conductor) inhibited the reaction and that CdO (also an rc-type semi-conductor) catalyzed the reaction, were not consistent with this explanation. It was noted, however, that both NiO and CdO could be reduced by the product caesium metal, whereas ZnO is not, and that the reaction with NiO yielded caesium oxide, which is identified as the active catalyst. Detailed kinetic data for these rate processes are not available but the pattern of behaviour described clearly demonstrates that the interface reactions were more complicated than had been anticipated. 

In the search of high-performance SOFC anode, doped ceria have been evaluated as possible anode materials [9,10]. Comparing Ni-samaria-doped ceria (SDC) with Ni-YSZ, the Ni-SDC anode exhibits higher open-circuit voltages and a lower degree of polarization with either methanol as the fuel, as shown in Fig. 5, or methane as the fuel, as shown in Fig. 6. It was found that the depolarization ability of the anode is associated with the catalytic activity, the electrical conductivity, and the oxygen ionic conductivity of the anode materials [9]. It was also found that the anodic polarization and electro-catalytic activity strongly depend on the Ni content in the anode, and the optimum result for the Ni-SDC anode is achieved with 60... 

Approximate composition of individual hexaaluminate particles was measured by an analytical electron microscope to elucidate the correlation between hexaaluminate phases (Mn-rich and -poor) and Pr contents in the lattice (Figure 6). Although relative concentration of Sr to A1 was a constant at x=0, the composition of the particles in the sample was separated into two groups from their Sr/Al ratios and Mn contents. Pr ions are preferentially doped in the particles with small Mn/ A1 ratios at x=0.2. With an increase in Pr concentration, the number of Pr-poor particles decreased and their Mn/Al ratios approached to those of Pr-rich particles at x=0.4. The substitution of Mn for Al site compensates excess charge of Pr3+ in the hexaaluminate lattice and leads to an increase of Mn in the hexaaluminate particle. It is considered that ease of reduction-oxidation cycle was influenced by the compensation and gave rise to increase in catalytic activity for... 

Metal ions or their oxides were combined with Ti02 nanomaterials in order to improve the catalytic activity and selectivity of the Ti02 photocatalysts. Ag-doped Ti02 was used to degrade gaseous sulfur compounds [158], Ag nanoparticle-doped Ti02... 

In order to explain the catalytic activity of PANI, we have modeled the electronic structure of doped molecular PANI clusters and its adsorption complexes with oxygen and hydrogen. The geometric and electronic... 

The main concept for development of metal-air batteries with new low-cost composite polymeric catalysts is to use catalytic activity of PANI/TEG composition towards the oxygen reduction during the discharge process of battery side by side with non-Faradaic process of anion doping during the charge process (please, see schemes below). 

Querino, do Carmo Rangel, and coworkers—improvement in catalytic activity by doping Pt/zirconia with Ce. Querino et al.469 reported that doping of a fraction of approximately 0.1 Ce to Pt/Zr02 led to enhanced activity for the high temperature shift reaction. The catalyst was prepared using a sol-gel synthesis... 

Ni-cermet type anodes have been improved by substituting the YSZ by ceria, gadolinium-doped ceria (GDC) and samarium-doped ceria (SDC). Ceria seems to increase the catalytic activity of the cermet for hydrogen oxidation, while SDC and GDC improve the ionic conductivity of the anode. Ni-ceria cermets are considered the main candidate for low-temperature SOFC [74],... 

Nitrogen doping has repeatedly been reported to increase the basic nature [182, 183] and catalytic activity [184,185] of the graphitic carbon which is attributed to the... 

For Fe-based nitrogen-doped catalysts, the catalytic activity is directly related to iron content the number of catalytic sites is increasing as Fe content is increasing until all phenanthroline nitrogens are coordinated with iron [212]. 

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