Experiments have shown that nanoscale ripples in a graphene membrane exhibit unexpectedly high catalytic activity with respect to hydrogen dissociation. Nonetheless, the catalytic selectivity of nanorippled graphene remains unknown, which is an equally important property for assessing a catalyst's potential and its fit-for-purpose applications. Herein, we examine the catalytic selectivity of nanorippled graphene using a model reaction of molecular hydrogen with another simple but double-bonded molecule, oxygen, and comparing the measurement results with those from splitting of hydrogen molecules. We show that although nanorippled graphene exhibits a high catalytic activity toward hydrogen dissociation, the activity for catalyzing the hydrogen–oxygen reaction is quite low, translating into a strong catalytic selectivity. The latter reaction involves the reduction of oxygen molecules by the dissociated hydrogen adatoms, which requires additional energy cost and practically determines the selectivity. In this sense, the well-established information about reactions in general of atomic hydrogen with many other species in the literature could potentially predict the selectivity of nanorippled graphene as a catalyst. Our work provides implications for the catalytic properties of nanorippled graphene, especially its selectivity. The results would be important for its extension to a wider range of reactions and for designer technologies involving hydrogen.

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纳米波纹石墨烯的催化选择性

实验表明，石墨烯膜中的纳米级波纹对于氢解离表现出出乎意料的高催化活性。尽管如此，纳米波纹石墨烯的催化选择性仍然未知，这对于评估催化剂的潜力及其适合用途的应用来说是同样重要的特性。在这里，我们使用分子氢与另一种简单但双键分子氧的模型反应来检查纳米波纹石墨烯的催化选择性，并将测量结果与氢分子分裂的测量结果进行比较。我们发现，虽然纳米波纹石墨烯对氢解离表现出很高的催化活性，但催化氢氧反应的活性相当低，转化为很强的催化选择性。后一种反应涉及通过解离的氢吸附原子还原氧分子，这需要额外的能量成本并且实际上决定了选择性。从这个意义上说，文献中关于原子氢与许多其他物质的一般反应的既定信息可以潜在地预测纳米波纹石墨烯作为催化剂的选择性。我们的工作对纳米波纹石墨烯的催化性能，特别是其选择性提供了启示。这些结果对于将其扩展到更广泛的反应以及涉及氢的设计技术非常重要。