Plastics are a climate problem. Making precursors for common plastics, such as ethylene and carbon monoxide, consumes fossil fuels and releases plenty of carbon dioxide. In recent years, chemists have devised bench-top reactors called electrochemical cells that aim to reverse the process, starting with water and waste carbon dioxide from industrial processes and using renewable electricity to turn them into feedstocks for plastics. But that green vision has a practical problem: The cells often consume highly alkaline additives that themselves take energy to make. Now, two groups are reporting strides toward solving the alkalinity hurdle. One advance links two electrochemical cells in tandem to bypass the problem altogether, and another turns to an enzymelike catalyst to generate a desired chemical without consuming alkaline additives.

塑料是气候问题。制备普通塑料的前体，例如乙烯和一氧化碳，会消耗化石燃料并释放大量二氧化碳。近年来，化学家设计出了称为电化学电池的台式反应器，旨在改变这一过程，首先是将水和工业过程中产生的二氧化碳废料，然后利用可再生电力将其转化为塑料原料。但是，绿色视野存在一个实际问题：细胞通常会消耗高度碱性的添加剂，而这些添加剂本身就需要消耗能量。现在，有两个小组报告正在朝着解决碱度障碍的步伐迈进。一种进展是串联连接两个电化学电池以完全绕过该问题，另一种进展是使用酶样催化剂来生成所需的化学物质而不消耗碱性添加剂。