Disclosed is an anode electrode including a nitride semiconductor layer. This nitride semiconductor layer includes an Al.sub.xGa.sub.1-xN layer (0<x0.25), an Al.sub.yGa.sub.1-yN layer (0yx), and a GaN layer. The Al.sub.yGa.sub.1-yN layer is interposed between the Al.sub.xGa.sub.1-xN layer and the GaN layer. The value of x is fixed in the thickness direction of the Al.sub.xGa.sub.1-xN layer. The value of y decreases from the interface with the Al.sub.xGa.sub.1-xN layer f toward the interface with the GaN layer. The Al.sub.xGa.sub.1-xN layer is irradiated with light having a wavelength of 360 nm or less so as to reduce carbon dioxide.

Disclosed is an anode electrode including a nitride semiconductor layer. This nitride semiconductor layer includes an Al.sub.xGa.sub.1-xN layer (0<x0.25), an Al.sub.yGa.sub.1-yN layer (0yx), and a GaN layer. The Al.sub.yGa.sub.1-yN layer is interposed between the Al.sub.xGa.sub.1-xN layer and the GaN layer. The value of x is fixed in the thickness direction of the Al.sub.xGa.sub.1-xN layer. The value of y decreases from the interface with the Al.sub.xGa.sub.1-xN layer f toward the interface with the GaN layer. The Al.sub.xGa.sub.1-xN layer is irradiated with light having a wavelength of 360 nm or less so as to reduce carbon dioxide.

In alternative embodiments, provided are processes for producing propylene glycol from glycerol derived from manufacturing biodiesel. Processes as provided herein can reduce color and/or odor from a converted propylene glycol by removing impurities and by-products produced during the glycerol hydrogenation conversion process. In alternative embodiments, provided are improved process for producing propylene glycol from glycerol at high selectivity and conversion and reduced operating costs.

An efficient one step, one pot process of synthesis of value-added products such as diols, monools and/or acids, preferably 1,2-PG from sugars/polysachhrides is disclosed. The process is catalyzed by a bimetallic catalyst supported on alumina and the catalyst is recyclable. The process of synthesis of the catalyst is a simple process and it converts a high % of the substrates to the desired polyols under mild conditions.

An efficient one step, one pot process of synthesis of value-added products such as diols, monools and/or acids, preferably 1,2-PG from sugars/polysachhrides is disclosed. The process is catalyzed by a bimetallic catalyst supported on alumina and the catalyst is recyclable. The process of synthesis of the catalyst is a simple process and it converts a high % of the substrates to the desired polyols under mild conditions.

Disclosed herein is a metal oxide aerogel catalyst for hydrogenation and/or hydrodeoxygenation, a method for preparing the same, and a method for hydrogenation and/or hydrodeoxygenation using the same. The catalyst consists of a metal and an oxide thereof, and the catalyst is in a form of an aerogel produced by supercritical drying. The catalyst has an effect of providing high hydrogenation and/or hydrodeoxygenation efficiency of an oxygen-containing compound.

Disclosed herein is a metal oxide aerogel catalyst for hydrogenation and/or hydrodeoxygenation, a method for preparing the same, and a method for hydrogenation and/or hydrodeoxygenation using the same. The catalyst consists of a metal and an oxide thereof, and the catalyst is in a form of an aerogel produced by supercritical drying. The catalyst has an effect of providing high hydrogenation and/or hydrodeoxygenation efficiency of an oxygen-containing compound.