Abstract: The present invention provides an exhaust gas purification catalyst comprising a base material, and a two or more layered catalyst coating layer, formed on the base material, wherein the two or more layers have upper and lower layers, and wherein the upper layer contains a large amount of noble metal per liter of the base material more than that of the lower layer, and the lower layer contains a large amount of an oxygen storage/release material per liter of the base material more than that of the upper layer. This exhaust gas purification catalyst has more excellent H2S purifying performance than conventional catalysts while maintaining purifying performance against NOx and the other exhaust gas components.

Abstract: Disclosed herein is a hydrogen sulfide production-suppressing member, comprising: a sulfur-adsorbing portion 2 comprising an oxide comprising at least ceria, the sulfur-adsorbing portion 2 being disposed upstream side of an exhaust gas; and a sulfur-releasing portion 3 being disposed downstream side of the sulfur-adsorbing portion 2 and having surface acidity higher than that of the sulfur-adsorbing portion 2. SOx adsorbed on the sulfur-adsorbing portion is released in a high-temperature zone, but the released SOx, is difficult to adsorb on the sulfur-releasing portion 3, and thus is not adsorbed again. Thus, the production of H2S is suppressed without using environmental loading substances such as nickel.

Abstract: An apparatus for purification of exhaust gas comprises: an exhaust gas pipe (2) connected to an internal combustion engine (1); an upstream catalyst (3) arranged at the upstream side of an exhaust gas passage inside the exhaust gas pipe (2); a downstream catalyst (4) which is arranged at the downstream side of the exhaust gas passage inside the exhaust gas pipe (2), and on which nickel and/or iron is supported; and oxidizing gas supply means (5) which is connected to the exhaust gas pipe (2) between the upstream catalyst (3) and the downstream catalyst (4), and which supplies oxidizing gas into the exhaust gas pipe (2).

Abstract: Decreasing hydrogen sulfide emission without using nickel is made possible. An exhaust gas-purifying catalyst includes a support substrate, a catalyst support layer supported by the support substrate and including porous carrier, and a precious metal supported by the porous carrier. A mean diameter of the precious metal is 5 nm or larger.

Abstract: The present invention provides an exhaust gas purification catalyst comprising a base material, and a two or more layered catalyst coating layer, formed on the base material, wherein the two or more layers have upper and lower layers, and wherein the upper layer contains a large amount of noble metal per liter of the base material more than that of the lower layer, and the lower layer contains a large amount of an oxygen storage/release material per liter of the base material more than that of the upper layer. This exhaust gas purification catalyst has more excellent H2S purifying performance than conventional catalysts while maintaining purifying performance against NOx and the other exhaust gas components.

Abstract: An NOx sorption-and-reduction type catalyst is made which includes a hydrogen generating catalyst in which Rh is loaded on a support including an Al2O3—ZrO2 composite oxide. Since the Al2O3—ZrO2 composite oxide exhibits a basicity lower than ZrO2, SOx are less likely to approach so that it is possible to suppress the sulfur poisoning of Rh. Moreover, the Al2O3—ZrO2 composite oxide exhibits higher heat resistance than ZrO2, and it has a function of improving the steam reforming reaction activity of Rh in the same manner as ZrO2. Therefore, the post-durability NOx purifying ability of the NOx sorption-and-reduction type catalyst is improved.

Abstract: A noble metal and an NOx sorption member are loaded on a support which includes composite particles having a structure including a core portion in which ZrO2 is a major component and a superficial portion formed on a surface of the core portion and including an oxide, whose basicity is lower than ZrO2, more than the core portion. The composite particles exhibit a high basicity at the inside and a low basicity on the surface by Al2O3 or TiO2 which exists more in the surface. Accordingly, the sulfur-poisoning resistance is improved, and, at the same time, the post-durability NOx purifying ability is improved.

Abstract: A catalyst for purifying exhaust gases which can suppress an active ingredient, such as an alkali metal, which reacts with a substrate from moving to the substrate, thereby preventing a decrease in strength such as thermal shock resistance of the substrate. In production, first, a first oxide layer composed mainly of an oxide which has a high reactability with the active ingredient is formed on the substrate. Next, a second oxide layer composed mainly of an oxide which has a low reactability with the active ingredient is formed on the first oxide layer. Then, a catalyst layer loaded at least with a noble metal and the active ingredient is formed on the second oxide layer. This second oxide layer suppresses transfer of the active ingredient and some active ingredient which has passed through the second oxide layer is caught by the first oxide layer owing to its reaction.

Abstract: An NOx sorption-and-reduction type catalyst is made which includes a hydrogen generating catalyst in which Rh is loaded on a support including an Al2O3—ZrO2 composite oxide. Since the Al2O3—ZrO2 composite oxide exhibits a basicity lower than ZrO2, SOX are less likely to approach so that it is possible to suppress the sulfur poisoning of Rh. Moreover, the Al2O3—ZrO2 composite oxide exhibits higher heat resistance than ZrO2, and it has a function of improving the steam reforming reaction activity of Rh in the same manner as ZrO2. Therefore, the post-durability NOx purifying ability of the NOx sorption-and-reduction type catalyst is improved.

Abstract: A noble metal and an NOx sorption member are loaded on a support which includes composite particles having a structure including a core portion in which ZrO2 is a major component and a superficial portion formed on a surface of the core portion and including an oxide, whose basicity is lower than ZrO2, more than the core portion. The composite particles exhibit a high basicity at the inside and a low basicity on the surface by Al2O3 or TiO2 which exists more in the surface. Accordingly, the sulfur-poisoning resistance is improved, and, at the same time, the post-durability NOx purifying ability is improved.

Abstract: This catalyst for purifying exhaust gases can suppress an active ingredient, such as an alkali metal, which reacts with a substrate from moving to the substrate, thereby preventing a decrease in strength such as thermal shock resistance of the substrate. In production, first, a first oxide layer composed mainly of an oxide which has a high reactability with the active ingredient is formed on the substrate. Next, a second oxide layer composed mainly of an oxide which has a low reactability with the active ingredient is formed on the first oxide layer. Then, a catalyst layer loaded at least with a noble metal and the active ingredient is formed on the second oxide layer. This second oxide layer suppresses transfer of the active ingredient and some active ingredient which has passed through the second oxide layer is caught by the first oxide layer owing to its reaction.

Abstract: A catalyst for purifying exhaust of an internal combustion engine is prepared by mixing first powders in which at least Pt is loaded on a first support and second powders in which at least Rh is loaded on a second support and loading NOx occluding material, for example an alkaline-earth metal, alkali metal or rare-earth metal, at least on the first support. In such catalyst, the second support is made of a stabilized zirconia stabilized by alkaline-earth metal or rare-earth element. The second support, having been become alkaline by the alkaline-earth metal or the rare-earth element, is excellent in absorbing performance of the steam (H2O), so that the steam reforming reaction by Rh advances sufficiently. Therefore, the created hydrogen greatly contributes to the reduction of NOx and to the sulfur poisoning prevention of the NOx occluding material.