Herein, we investigated the effects of aging time and temperature on the performance of co-precipitation-prepared Cu-Zn-Al catalysts in the low-temperature water-gas shift (LT-WGS) reaction. The highest CO conversion within the employed temperature range as well as very stable activity over 200 h were observed for the catalyst prepared at 80 degrees C and aged for 72 h, which was ascribed to its high surface area and close-to-100% degree of CuO reduction. Conversely, catalysts aged at temperatures below 80 degrees C had poor physical properties, while aging for <72 h resulted in the formation of bulk copper oxide, which was hardly reduced under the low-temperature conditions. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.