## 1 Introduction  
Nowadays, environment preserving is one of the major issues facing the world. Alongside with technological progress, human activities contribute to increasing levels of air pollution caused by volatile organic compounds (VOCs). The protection of environment and human health imposes developing of effective strategies for reduction of global VOCs emission. Among the variety of technologies for VOCs removal, complete catalytic oxidation exhibits advantages, making it efficient, environmentally friendly and economically feasible method for elimination of VOCs. Several reviews cover recent progress in research focused on the catalytic oxidation of VOCs, including design of appropriate catalytic systems, their stability and durability, resistance to deactivation, and mechanism of various VOCs destruction [1; 2; 3; 4; 5]. Two types of catalysts, in particular, noble metal-based and transition metal oxides, are most intensively studied [6]. Significant attention is given to the noble metal-based catalysts, because they demonstrate high activity at low temperatures, better stability and can be regenerated [7; 8]. Over the past thirty years, supported gold catalysts have exhibited remarkable activity in oxidation of various VOCs and continue to attract the interest of the catalytic community [9; 10; 11]. Considerable efforts have been focused on elucidating the effect of preparation methods on gold particle size and oxidation state, role of support effects, relationship between electronic and structural properties of the gold-based catalysts, and catalytic performance. The nature of support has also been highlighted due to its decisive role on the size, shape and amount of supported gold [10]. The proper selection of support is a task of particular importance because in many cases metal oxide is not merely a carrier of gold nanoparticles, but participates actively in reaction mechanism. This observation is especially relevant when supporting material is reducible oxide. In this context, ceria-based systems have received a special attention for VOCs catalytic combustion [12; 13; 14; 15]. Unique catalytic properties of ceria originate from its defective chemistry and its ability to exchange rapidly lattice oxygen with the gas phase, thus enhancing catalytic activity at the interfacial metal-support sites. Catalytic performance can be additionally affected by modification of ceria with different metal ions due to improvement of oxygen mobility and reducibility. Recently, we studied the effect of Y-doping of ceria (1, 2.5, 5 and 7.5 wt.% Y\({}_{2}\)O\({}_{3}\)) on the activity in complete benzene oxidation (CBO) of supported gold catalysts [16]. The best performance (100% conversion at 250 \({}^{\circ}\)C) exhibited gold supported on ceria doped with 1 wt. % Y\({}_{2}\)O\({}_{3}\) using the impregnation method. Considering the suitability of Pd-based catalysts for low-temperature VOCs oxidation [7; 17; 18; 19] and special interest in bimetallic Au-Pd system as attractive catalytic material for this reaction [20; 21; 22], we compared catalytic behaviors in CBO of Au, Pd and Pd-Au catalysts supported on ceria and on Y-doped ceria [23]. Pd-Au sample exhibited superior activity (100% conversion at 150 \({}^{\circ}\)C) and stability over a period of more than 70 h, which is quite promising behavior in the case of practical application. From an economic point of view, the design of high performing and cost-effective catalyst formulations includes the search for appropriate and economically viable supports. Deposition of highly dispersed particles on high surface area support, in particular, alumina modified by well surface dispersed suitable metal oxide, as this would maximize the activity per mass of noble metal. In this way, having in mind gold catalysts, it is possible to achieve a greater interfacial area between the gold nanoparticles and alumina-supported metal oxides. We have already mentioned the relevance of ceria usage.