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A novel Pt/CeO2–ZrO2–Bi2O3catalyst was prepared to realize complete CO oxidation at room temperature or below even in the presence of moisture. Using this catalyst, a high CO oxidation activity and a high stability against moisture have been realized simultaneously. [ABSTRACT FROM AUTHOR]

Inorganic black pigments with thermal barrier characteristics, Ca 2 Mn 0.85- x Ti 0.15 Zn x O 4- x (0 ≤ x ≤ 0.10), were synthesized using a conventional solid-state reaction method in order to improve the blackness without decreasing the near-infrared (NIR) reflectance of a Ca 2 Mn 0.85 Ti 0.15 O 4 pigment, which was previously reported by our group. The composition was optimized to provide both high blackness and NIR reflection characteristics. As a result, the NIR solar reflectance value ( R NIR ) of Ca 2 Mn 0.77 Ti 0.15 Zn 0.08 O 3.92 ( R NIR = 74.6%) became larger than that of Ca 2 Mn 0.85 Ti 0.15 O 4 ( R NIR = 71.7%), and the black color tone of the former ( L * = 23.2, a * = +2.81, b * = +0.83, C = 2.93) was improved in comparison with that of the latter ( L * = 24.4, a * = +4.30, b * = +2.72, C = 5.09). This improvement is caused by the introduction of strain into the [MnO 6 ] octahedra and a decrease in the manganese ion concentration. The R NIR value of the Ca 2 Mn 0.77 Ti 0.15 Zn 0.08 O 3.92 pigment was also larger than those of the commercially available pigments ( R NIR < 53.0%). Therefore, Ca 2 Mn 0.77 Ti 0.15 Zn 0.08 O 3.92 has potential to be an inorganic black pigment for thermal shielding., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Ba(Zn 1- x Co x ) 2 Si 2 O 7 (0 ≤ x ≤ 0.50) solid solutions were synthesized as novel blue-violet inorganic pigments by a conventional solid-state reaction method. The crystal structure, optical properties, and colour of the pigments were characterized. All the pigments were obtained in a single-phase form. The pigments strongly absorbed visible light at wavelengths from 550 to 650 nm, corresponding to the range of green to orange light. This optical absorption was caused by the d-d transition of the tetrahedrally coordinated Co 2+ ( 4 A 2 (F) → 4 T 1 (P)), which was the origin of the blue-violet colour of the pigments. The most intense colour was obtained for Ba(Zn 0.85 Co 0.15 ) 2 Si 2 O 7 , where a * = +52.2 and b * = -65.5 in the CIE (Commission Internationale de l'Éclairage) L * a * b * system. These absolute values were significantly larger than those of commercial violet pigments such as Co 3 (PO 4 ) 2 ( a * = +33 and b * = -32) and NH 4 MnP 2 O 7 ( a * = +39 and b * = -21). Therefore, the Ba(Zn 0.85 Co 0.15 ) 2 Si 2 O 7 pigment could be a novel blue-violet inorganic pigment., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)